08-21-2011 10:40 AM - edited 08-21-2011 10:44 AM
Class refers to speed. Check your device manual for recommended card speeds. Lower numbered cards are cheaper, but higher rated numbers will minimized dropped frames and faster transfers to your computer. http://en.wikipedia.org/wiki/Secure_Digital#Speed_
- SD cards have a smaller FAT table and is limited to 2gb.
- SDHC cards have larger FAT table and can go to 32gb.
- SDXC cards can allow up to 2 terrabytes
08-21-2011 05:01 PM
XL - thanks very much for the prompt response & the very useful links to Wikipedia.
My newly ordered Canon camera will arrive in a couple of days, & I don't know yet what memory card is in it, but now I understand what sort of upgrade to buy, if I need one.