About SD Cards : Some General Knowledge

Secure Digital Cards

WHAT IS AN SD CARD?

SD stands for SECURE DIGITAL. These cards are very small flash memory like pen drives which means we can store any kind of data in that memory and we can also re-use that memory like we do in pen drives but SD cards are smaller than pen drives. A very small thing to store data in large quantities. 

Therefore, These are used in digital camcorders, digital cameras, handheld computers (PDAs) Personal Digital Assistants, audio players, and smartphones.

DO YOU KNOW THAT

These cards have types according to their space:

1. SDSC (SECURE DIGITAL STANDARD CAPACITY):
   These types of cards have only 128 megabytes to 4 gigabytes. 
2. SDHC (SECURE DIGITAL HIGH CAPACITY):
   These types of cards have 4 gigabytes to 32 gigabytes.
3. SDXC (SECURE DIGITAL EXTENDED CAPACITY):
   These types of cards have 64 gigabytes to 2 terabytes. (2 terabytes = 2048 gigabytes)

These cards also have classified according to their minimum constant speed:

1. Class 2: SD cards have a speed of 2 megabytes per second.
2. Class 4: SD cards have a speed of 4 megabytes per second.
3. Class 6: SD cards have a speed of 6 megabytes per second.
4. Class 10: This class has two types according to speed. 
1. UHS 1: SD cards have a minimum constant speed of 10 megabytes per second and a write speed of 80 megabytes per second.
2. UHS 3: SD cards have a minimum constant speed of 30 megabytes per second and a write speed of 240 megabytes per second.

TIP FOR BUYERS

Let me know if you have noticed that two SD Cards have the same space and same brand but they have different prices. Always see the type and class because the money for SDHC 4 GB Class 2 is cheaper than SDHC 4 GB Class 4, so whenever you are going to buy the SD Card don't buy one just because it is cheap without knowing its class. It is written on the wrapper and also on the SD Card.