What do the "Classes" mean on Transcend memory cards?

Question

What do the "Classes" mean on Transcend memory cards??

There are two transcend memory cards, both SDHC, both 8GB. One is class 6, the other class 2. Which one is better?? What does it mean?

Answer 1

SDHC cards have SD Speed Class Ratings defined by the SD Association. The SD Speed Class Ratings specify the following minimum sustained write speed on to empty SDHC cards:

Class 2: 2 MB/s

Class 4: 4 MB/s

Class 6: 6 MB/s