Quick question

[kos9399]

Before I start I would like to say that this is not a where to find roms or anything like that post im just in it for the homebrew .

 I just recently got a ds lite from a friend but it needs to be fixed(top screens busted and needs new case)but  I was wondering what is the difference in the r4 cards like the regular r4 then you have the r4-sdhc,r4III,then r4ultra.