Types of micro SD cards. Select a memory card: type, capacity, speed. Which one do I need?
Almost all GPS/GLONASS car navigators are equipped with an SD memory card reader designed for storing navigation software, map data and various multimedia information. Moreover, every user of modern digital technology has at least once been faced with the need to choose or purchase memory cards popular foriat SD, microSD, miniSD or their more “capacious brothers” - SDHC, microSDHC or miniSDHC. Everyone knows the names of these memory cards, and most of us are sure that microSD and microSDHC are synonymous words, meaning memory cards with absolutely the same characteristics. However, this is not quite true...
Physical dimensions of SD, SDHC memory cards
SD and SDHC memory cards are available in three dimensional formats:
- SD, SDHC - size (W*H*D): 32*24*2.1 mm;
- miniSD, mini SDHC - size (W*H*D): 21.5*20.0*1.4 mm;
- microSD, microSDHC - size (W*H*D): 11*15*1.0 mm.
Rice. 1 - Comparison of sizes of different dimensional formats of SD memory cards
Currently, memory cards of large formats microSD and SD are most widely used as storage media for GPS car navigators. Most manufactured SD memory cards have the overall microSD format, and an adapter to the SD format is sold in the kit, with which the card microSD memory Can be inserted into any regular SD card slot.
Rice. 2 - Comparative sizes of the Adapter (adapter), microSD card and 5-ruble coin
History of the emergence of SD, SDHC formats
Standard SD (Secure Digital Memory Card) was developed in August 1999 by Panasonic, SanDisk and Toshiba based on MMC memory card, and in 2000, Matsushita, SanDisk and Toshiba announced the creation of the SD Card Association.
All SD memory cards are equipped with their own controller and array of memory cells. Unlike MMC memory cards, the algorithm for writing to an SD memory card is designed in such a way that “illegal” reading of information is impossible, which is what was enshrined in the name - “Secure Digital”. The card can be protected with a password, without which it becomes practically inoperable. If the password is lost, then the only way to “restore the functionality” of the card is by reformatting it. Naturally, all data will be irretrievably lost. The SD card is also equipped with a mechanical write-protect switch. In the “lock” position, recording information, deleting files, and formatting the card are impossible. This is another way to prevent accidental loss of information. It should be taken into account that this type of protection (mechanical switch) is assigned to the device working with the card and may not be implemented. In most cases, SD can be replaced with an MMC card. Replacing in the opposite direction is usually not possible, since the SD is thicker and may simply not fit into the MMC slot.
So the standard SD is further development standard MMC. In terms of size and characteristics, SD cards are very similar to MMC, only slightly thicker. The main difference from MMC is copyright protection technology: the card has cryptographic protection against unauthorized copying, increased protection of information from accidental erasure or destruction, and a mechanical write-protect switch. The maximum capacity of SD memory cards is 4 GB.
Format SDHC (Secure Digital High Capacity) is a further development of the popular SD format (originally known as TransFlash, T-Flash), inheriting most of its characteristics. Potential maximum volume SDHC cards increased to 32 GB(for SD cards the maximum capacity is 4 GB). As a rule, the FAT32 file system is used to store information on SDHC cards (FAT16/32 was used for SD).
So what are the differences between SD and SDHC memory cards?
The key innovation for SDHC cards, which allowed them to exceed the capacity of 4GB, was introduction of sector-by-sector addressing(similar to hard drives), while regular SD cards have byte addressing (like RAM) and, accordingly, with a 32-bit address they can have a capacity of no more than 4GB. Thus, SD and SDHC memory cards require completely different principles for accessing their memory cells. SDHC memory cards are not compatible with devices that are natively designed only for SD cards, but devices that are capable of working with SDHC cards also support SD cards.
Data transfer speed of SD and SDHC cards
Association of Card Manufacturers - SDCard Association for the purpose of unification, introduced a classification of speed characteristics of SDHC cards and devices for working with them, the so-called SD Speed Class :
- SD Class 2 - recording speed of at least 2 MB/s;
- SD Class 4 - recording speed of at least 4 MB/s;
- SD Class 6 - recording speed of at least 6 MB/s;
- SD Class 10 - write speed of at least 10 MB/s.
The recording speed in accordance with this classification is indicated in technical specifications to a memory card, for example recording: MicroSDHC memory card (Class 4) - means that this map The memory has a microSDHC format and allows you to write data to it with a guaranteed minimum speed of 4 MB/s.
The reading speed of SD and SDHC memory cards is usually 2...4 times higher than the writing speed and is often not indicated in the specifications for the memory card.
Be careful when choosing SD memory cards and check with the seller and manufacturer about the type of memory cards supported by your car navigator!
Based on Wikipedia materials - http://ru.wikipedia.org
Every person who constantly works on a computer urgently needs to have such an irreplaceable thing as a USB drive. This can be either a simple flash memory card or a larger multi-gigabyte drive that is needed to transfer information. Today we’ll try to decide which is the best USB flash card to choose for solving various problems.
Which flash drive to choose depends on the amount of information you are transferring. In fact, our drive has a lot of functions. First of all, it's volume. If you need to transfer small information, it is not necessary to buy a small flash drive. At the same time, the difference in price for 2 gigabytes, 4 gigabytes and 8 gigabytes will not be large. By choosing an 8 GB storage medium, you will benefit in both price and quality. Today, many drives write at good speed. The download speed is ten megabits/s, but they read on average in fifteen megabits/s.
Types and classes of flash memory cards
Of course, there are also very fast flash drives. That is, you need to pay attention to the specific model of the flash drive you are buying. If you find the words “ultra fast” or “hi-speed” on it, then this is a wonderful model with high writing and reading speeds. In general, all flash drives are divided into types and classes.
SD (Secure Digital) is a portable flat memory card standard designed for use in portable devices - cameras, cameras, etc. Classified into the following classes:
Since this storage format is very popular, an SD card, thanks to various adapters, can be used with almost any device, be it a computer, laptop or even a tablet - via a card reader or directly via USB.
miniSD and microSD (TransFlash) are types of SD cards that can be used to connect to an SD slot using a special adapter. Mini is also often used in cameras, while Micro is often used in smaller devices such as phones, tablets, and video recorders.
SDHC (Secure Digital High Capacity) is another more modern type of SD, characterized by greater speed. Outwardly, they do not differ from SD, but they can only work with those devices that specifically indicate support for cards of this type. Sometimes it happens that the device becomes able to work with SDHC after a firmware update. Such cards are available in capacities from 4 to 32 GB.
SDXC (Secure Digital eXtended Capacity) are SD flash cards with extended capacity.
SD 3.0 – cards with a capacity of 64GB and a maximum speed of up to 90 MB/sec, which may be compatible with some existing SDHC devices
SD 4.0 speed is up to 300MB/sec, and the card capacity can be from 64GB to 2TB. They are not fully compatible with SDHC devices.
Which USB flash drive to choose?
Quality and reliability depend in direct proportion not only on the class, but also on the manufacturer you choose. Samsung, Transcend, SanDisk and Kingston are considered famous flash drives for their quality products. And besides, you can find flash drives good quality from companies such as PQI, Lexar, Pretec and Imation.
It also happens that brands that no one knows use other people’s devices in the production of cases with their logo. You shouldn’t refuse them either, since with the same components they are much cheaper, that is, you won’t overpay for the brand.
It is worth noting that the external size of a USB drive does not affect its actual capacity. You can also find very small flash drives that are similar in size to SIM cards. Here it’s a matter of each person’s taste - a small drive or a large one, but the price of small cards is more expensive and it’s also easier to lose them.
I hope the described points will help you choose a USB flash drive that will facilitate the fastest and most secure work on your computer. When choosing, we choose popular manufacturers, but do not forget about little-known companies with components from well-known companies - it is cheaper with the same quality.
Well, for a snack today – a video about how to find out the real size of your flash drive. Bye!
Our modern life in all areas is connected with technology - cameras, smartphones, tablets, and laptops.
Thirty or forty years ago, no one would have dreamed of creating smart hair dryers, window washers, etc., but we now have this too!
With this abundance of available information, there is a reasonable need for a device, compact and convenient, that would help store all this information.
It is for these purposes that memory cards were developed.
Trend towards minimal size and weight electronic devices, along with an increase in their functionality, did not pass by memory cards.
Following the requirements of the present time, they also became more spacious in volume and more compact in size.
A modern miracle of technology is literally a few millimeters of plastic with enormous information storage capabilities. Our article is about them.
If you have a phone or tablet, you like to watch TV shows, download music, download funny and beautiful photos from the Internet - and maybe all together - then the question of how you can increase the built-in memory of your device will be especially interesting to you.
Believe me, sooner or later any native memory of even a very expensive smartphone will run out - and flash memory cards will be an excellent addition to increase the memory of your phone.
Just as there are different manufacturers, companies and classes of manufacturers, memory cards also differ among themselves. We will try to look at their main types, the differences between them and their functionality. And for those who read the article to the end - a pleasant surprise - a review of the five most popular and high-quality microSD cards from different manufacturers.
Types of memory cards
Memory cards, like any other device, have gone through their own evolutionary path:
Currently, removable storage media are becoming increasingly popular - they are in no way inferior in terms of memory capacity, but attract equipment manufacturers with their compact size.
Accordingly, an increasing number of equipment manufacturers are producing phones, tablets, cameras and other portable equipment with support for memory cards in the micro-SD format.
If you have a camera, camera or old model that supports SD cards - Now it’s not a problem to use micro-SD with them too, but using a special adapter.
How it looks, look at the photo:
Using microSD cards inserted into the adapter - and you can use it as a full-fledged SD card:
The adapter will also help you transfer data from your phone's micro-SD card to your computer.
In addition, if you do not use micro-SD, it is convenient to store it inside the adapter so as not to lose or damage it due to its small size.
Differences between cards depending on memory size:
If ten years ago you could boast of 128 MB of volume, now consumer demands have increased significantly. Cards of different sizes are available in the market. Naturally, the higher the number, the higher the price. I would also like to mention that a memory card with a large capacity, especially a high-quality one, cannot be cheap. for a 32GB memory card from a well-known manufacturer, the market price is from $15, respectively, a larger volume is more expensive. And purchasing a memory card from well-known manufacturers is safer and more profitable - if only because they are covered by a warranty.
How to choose a memory card
Pay attention e when purchasing using information printed on the front of the card itself.
Usually this is enough to have a general idea of it, as well as to distinguish a counterfeit from the original.
The main indicators are speed class, device compatibility class and support for the UHS-I interface - their location can be seen in the diagrams above.
In the table for your attention how to decipher the icons on the front side of memory cards:
microSD formats
The main advantage of MicroSD and MicroSDXC cards is their higher capacity and writing speed, and they require separate compatibility than MicroSD cards.
That is, a device that reads MicroSD may not read MicroSDHC and MicroSDXC at the same time.
Flash drive classes
The quality of memory and data processing speed depend on the class of the memory card.
Let us clarify that each card has two speed indicators - data reading speed and data writing speed; and if you require MicroSD card into a video camera or, the speed of data recording will be of great importance - otherwise the quality of the video may deteriorate or photos may disappear during high-speed shooting.
The class of a memory card is usually indicated by the sign C
It is usually customary to talk about the existence of 4 types of cards
- 2: write at 2MB/s;
- 4: 4 MB/s;
- 6: 6 MB/s;
- 10: 10 MB/s.
For high-quality video recording, cards with the abbreviation UHS were invented. Their class is indicated by the symbol U.
- UHS Speed Class 1: min. speed 10 MB/sec.
- UHS Speed Class 3: min. speed 30 MB/sec.
Decide which card is right for you
It's quite simple if you consider your basic needs:
- 2-4 classes will be enough to listen to the playlist, watch videos in medium quality and low resolution;
- 6th or 10th grade will be needed if you use devices that support HD and Full HD format;
- UHS is the top option - if you have a device with HD and Full HD recording formats, then this format is for you, as it provides high recording speed.
What problems may be associated with the wrong choice of memory card:
- slow playback and recording of video on the device;
- long file storage;
- inability to watch videos high resolution HD and Full HD (or very slow playback);
- limited use of applications on the device: they either cannot load due to lack of memory, or may play slowly. This is especially true for games with high graphics - crashes and failures are possible.
- When shooting a series of photos at high speed and selecting a memory card with a low recording speed, some photos may be damaged or lost. This also applies to recording in high resolution - some parts of the video may be rejected.
Additional nuances
Again, everything is tailored to your needs.
If you are a reporter, a traveler, or just a fan of taking pictures outdoors in conditions that are not very suitable for this, you will be interested in the option of a memory card with moisture protection and heat-resistant functions. Such cards will be guaranteed against falling into water, temperature changes, and bad weather in the form of snow and rain.
If you are an athlete or like to shoot on the move, there are memory cards that are resistant to damage when dropped - they are designed for use in extreme conditions.
Rarer models can even take into account protection against x-rays, vibration and magnetic waves.
If you work in mass marketing, some large manufacturing companies have a service - printing an image of your choice onto memory cards.
Before purchasing, it is important for you to make sure that your device supports memory cards. of this format- if in doubt, it is better to take the device with you when purchasing and consult with a specialist.
For example, UHS format cards are designed for high-end flagship devices that support the function - and may not be compatible with low-end devices. The road itself is not always the best in every sense.
If you buy online, every major company has online service support.
Quality
There are companies that have made a worldwide name for themselves and produce removable memory media. These are Samsung, Lexar, etc.
It is important to be aware that when buying a cheap card from an unknown manufacturer, you are taking a risk rather than spending your money wisely.
Naturally, a quality product, especially one with a warranty period, cannot be cheap.
And what becomes especially offensive is not so much the money spent, but the lost data, which is then difficult, and sometimes impossible, to recover.
In addition to greater reliability and safety of your data, with a branded card you will receive high speed and a guarantee (in some cases, even lifetime).
Fakes
No one is currently safe from purchasing counterfeit products. It's not so much a matter of the seller's fame and the store's guarantee - they usually counterfeit removable media and now the market is filled with them. If we analyze the market and check the sold memory cards, it is established that up to a third of them were fake.
In the photo above, you can even guess without a signature which of the cards was original and which was a crude fake.
But now the catch is that pirate companies have learned to make quite beautiful fakes that are indistinguishable from the original.
How can you tell if it's a fake flash card?
- it is sold at a significantly lower price. Those. We are not talking about normal market price regulation or various promotions when it is at a discount - it is simply sold at a price 2-3 times lower than the same card, for example, in the official store of this brand. This should be alarming.
- Look carefully at the front side of the card, at the quality of the markings and printing of the package. Everything should be clear and beautiful, the colors should be bright, and the company name should not be distorted.
- There are special programs for checking the originality of a memory card - H2testw for Windows and F3 for MacOS and . But in this case, you must purchase it first.
Bonus for readers - top MicroSD 2018
This is the top choice of many consumers, which cards they considered the highest quality and best, assessed by sales volumes.
Kingston microSDXC Class
| Advantages |
|
|---|---|
| Flaws | There is no support for some options for simultaneous video recording and photography |
| Our conclusion | One of the advantages is the large amount of memory that allows you to store a huge amount of information. |
| Capacity standard | SDXC |
| Volume | 128 GB (256 GB) |
| Performance | Reading – up to 45 MB/s Recording – up to 10 MB/s |
| Class/Tire | UHS-I U1, Class 10 |
| Protection |
|
Samsung microSDXC Evo Plus 64GB
| Advantages |
|
|---|---|
| Flaws | Not all file systems are formattable. |
| Our conclusion | The Samsung Evo series is an excellent choice for all extreme sports enthusiasts and water sports enthusiasts. It is compatible with UHS-I Speed Class 1(U1) and Class 10 cards and is designed for Full HD video recording |
| Capacity standard | SDXC |
| Volume | 64 GB (128 GB) |
| Performance | Read speed – up to 80 MB/s Write speed – up to 20 MB/s |
| Class/Tire | UHS-I U1, Class 10 |
| Protection |
|
Transcend microSDHC Class 10 32GB
| Advantages |
|
|---|---|
| Flaws | RecoveRx's formatting and password protection features are only available under . |
| Our conclusion | A card with an excellent level of protection for your data both from external influences and from errors. that may arise during data transfer, for which the built-in ECC technology is responsible. |
| Capacity standard | SDHC |
| Volume | 32 GB (4 GB, 8 GB, 16 GB) |
| Performance |
|
| Class/Tire | Class 10 |
| Protection |
|
Kingston microSDHC Class 10 U3 UHS-I
| Advantages |
|
|---|---|
| Flaws | Not particularly suitable for transferring large amounts of information |
| Our conclusion | One of Kingston's top models processes information quickly. Ideal for all modern gadgets |
| Capacity standard | SDHC |
| Volume | 32 GB |
| Performance |
|
| Class/Tire | UHS-I U3, class 10 |
| Protection |
|
SmartBuy microSDHC Class 10
| Advantages |
|
|---|---|
| Flaws | Performance was expected to be higher |
| Our conclusion | Combines quality and low price and allows you to store a small amount of information |
| Capacity standard | SDHC |
| Volume | 32 GB (4 GB, 8 GB, 16 GB) |
| Performance | Data transfer – 4 MB/s |
| Class/Tire | Class 10 |
| Protection | No data available |
Sandisk Extreme Pro SDXC UHS Class 3
If you are a professional photographer and use a camera as a means of earning money, your camera's memory card should work flawlessly.
A 15-20 megabit record could be filled in 7-10 photos and that would be the end of it. Sandisk Extreme Pro SDXC UHS Class 3 will help solve this complexity.
Information can be written to it at lightning speed, approximately 90-95 megabits per second.
The amount of information required for work and entertainment is increasing every day. The quality of photographs and video files increases, and along with it their “weight” also increases. As a result, the built-in memory of our gadgets, especially those from the budget segment, is sorely lacking. This problem can be easily solved, especially in phones with a removable battery. Why in them, how to choose a memory card for a phone for any budget and many other issues will be discussed in this article.
Memory card. What is this?
As a rule, the memory card is a small black rectangle, but sometimes appearance is different. Depending on the model, it has a different amount of memory. Modern models of various gadgets use only one type of memory card - microSD, although there are quite a large number of them.
Previously, when Cell phones As soon as they began to acquire additional memory, each manufacturer tried to invent its own format, different from the others. For example, the memory card of an LG phone could not be installed in a Nokia. Over time, this trend, as well as specific charging connectors, gradually faded away. This has its own advantage, because after changing your smartphone, you now don’t have to re-purchase this important accessory for it.
How much volume do I need?
When it comes to the required capacity of an SD Card, you should first ask yourself what files you work with most often. In order to get your bearings at least a little, you can take a look at the following list, showing the approximate size of the files we are used to:
- Melody or track - from 3 to 10 megabytes.
- Photo - from 1 to 5 megabytes.
- Film (depending on quality) from 700 megabytes to several gigabytes.
If you are used to using only high-quality content, then you will have to think about memory cards of 32 GB or more. If the card is needed only to store a small playlist and current photos, its volume can be easily calculated using the above information. We can definitely say that with large volumes of photos, there will not be enough internal space, and a memory card is required. A phone with 2 GB of memory is simply not capable of storing the number of videos and photos that modern youth are accustomed to taking.
Feature regarding the capacity of the new memory card
Probably everyone who has previously encountered memory cards or flash drives has noticed that there is a little less space on them than stated by the manufacturer. Why does this problem occur and can it be fixed?
In reality there is no problem. The reason lies in the principles of computing space by a computer or telephone. We are accustomed to multiplying all quantities by a thousand, as, for example, there are a thousand grams in one kilogram. However, in the computer world, calculations are done a little differently, and a number of 1024 is considered to be one. As a result, such an error arises on the missing 24 bytes for every thousand. Therefore, manufacturers should not be blamed for such a “shortage”, and an SD memory card with “cut down” memory is actually quite normal.
What is a memory card class
All memory cards are divided not only by capacity, but also by class. Therefore, when you decide how to choose a memory card for your phone, do not forget about this parameter. The class displays the speed at which any information is written to it. There are cards of various classes, but the most popular in our stores are 4, 10 and U1.
In fact, everything is clear with digital classes - a four is equal to a write speed of up to 4 MB/s, and a ten is equal to up to 10 MB/s, respectively. With the U1 class it is a little more interesting, since manufacturers promise speeds not up to, but from 10 MB/s, but what the maximum possible will be, you have to check on the spot. This class is considered a newer standard, and the SD memory card marked with it differs in better side from their predecessors.
In addition to the above, there are also digital classes SD Card 2 and 6, as well as the new generation class U3. Digital are no different from their predecessors, that is, they correspond in the same way maximum speed records. Class U3 is considered to be this moment the highest and allows you to write information at speeds of over 30 MB/s. But despite high level development of smartphones, such a high speed is not yet needed by any of them, so we will not consider it in detail.
Which one do I need?
Let's look at what each class of memory card can be used for. This will be another step towards how to choose a memory card for your phone and not make a mistake.
- Class 2 memory cards are designed for data storage and are the slowest and cheapest option. You can record music and video files on them, but the recording process itself will be quite lengthy. Problems may occur when viewing high-definition videos.
- Class 4 memory cards are the most popular and common. Fully meet the speed needs of budget phones and smartphones related to multimedia files. Still, it’s better not to use it for games and programs.
- Class 6 memory cards - may already be a replacement internal memory some electronic devices and are designed for recording and storing any type of files.
- Class 10 memory cards are the fastest type of cards, the maximum capabilities of which can be used by any smartphone. Allows you to record video in high resolution and perform other tasks that require high-speed recording of information.
- U1 class memory cards are an improved class 10, with a slightly higher write speed and significantly faster reading, as a result of which they can be used for program files, since loading from them will be much faster.
- U3 class memory cards are used very rarely, since their characteristics are only needed when recording video in 4K resolution, and the cost is very high.
What is the maximum memory card capacity supported by the device?
Often, most manufacturers themselves indicate in the characteristics of a phone or smartphone what size memory card is recommended to be installed in the gadget. However, sometimes this information is not indicated directly, but using encoding different types kart. It's worth taking a look at the device specification and seeing which cards are supported. The following may be written there:
- microSD cards are an old standard that requires the installation of a phone micro memory card with a capacity of no more than 4 GB. Sometimes some Chinese manufacturers write that cards up to 8 GB are supported with the same marking, but no more.
- microSDHC cards are the most common format among budget phones and smartphones today. Provides the ability to expand memory with cards up to 32 GB, which is quite enough for most users.
- microSDXC cards - new format, allowing you to work with volumes up to 2 TB. Often, cards of this size can be very expensive, but a very popular, inexpensive, and functional solution would be to install additional memory of 64 or 128 GB.
How to decide on the manufacturer
In fact, there is not much difference between memory cards from different manufacturers. They are all quite reliable, so the final weighty argument when choosing can only be the price or attractive appearance. The speed of the card, as discussed above, depends only on its class.
Sometimes on older devices there is a situation where memory cards of the maximum capacity for the gadget do not work from all manufacturers. Even the developers of this or that gadget cannot answer what this is connected with. For example, a similar question was previously discussed on forums - I bought regular card memory, I didn’t see it point-blank, although it worked with other devices without problems. Therefore, when buying a memory card, it is best to take with you the device for which it is intended. This way you can avoid unnecessary stress associated with returning an incorrect accessory.
Instructions for installing a memory card
How exactly and where to place the card itself is often written in the user instructions for the device. However, there is often another missing important point. Some devices can easily read data written to a card with a file system of one of the common formats. But after prolonged use, failures may occur, which can lead to the loss of important information.
To prevent this from happening, it is recommended that immediately after installation, while there is no data on the card, you format it directly using your phone or smartphone. Don’t be lazy to do this operation, because later it can protect you from unnecessary worries. This concludes the recommendations on how to choose a memory card for your phone. We hope you will not have any problems purchasing this accessory.
Our computerized world is replete with all kinds of gadgets and accessories for them. Therefore, not everyone knows what an SD card is, what it is needed for and how many varieties there are.
Memory card and its features
A memory card is a small and fairly thin plate with a built-in flash memory module, which is non-volatile. This means that the information on it is retained even when it is removed from the device. Information can be deleted and rewritten many times. The service life of a memory card is calculated in decades. On some of them, information can be protected using certain methods.
Types of memory cards
At the moment, you can find many different types of memory cards on the market. In this article we will focus on the most popular types.
SD (Secure Digital) is the most popular type of memory card. It is used in many cameras, old players, tablets, camcorders, pocket computers and communicators. It can be purchased at all computer stores and communication stores for a fairly low price. The maximum capacity of such a card is 4GB.
SDHC cards include all SD memory cards larger than 4GB. This type of card is faster. Their maximum capacity is 32GB. It is preferable to purchase SDHC cards, but keep in mind that some older devices do not work with them.
SDXC is a new standard that is not yet widely adopted. Such cards are distinguished by their enormous capacity, which can reach 2 terabytes, and extremely high data writing speed. Their price is quite high, and they are not found on sale very often. In addition, this format is still supported by few devices today.
MiniSD is similar to SD, but smaller in size. Now it is practically not used, since it has been replaced by the microSD format, so buying it is problematic and expensive.
MicroSD differs from SD in its small size, and they are cheaper. True, it has one drawback - it is easy to lose, but on the other hand, it is very convenient, as it fits into any connector on any device. Now you know what an SD memory card is and what types you can purchase, and you are unlikely to be confused when choosing one.
