Yes, the 3DS has backwards compatibility to DS and DSi games.
Yes, you can use ds lite games in the original Nintendo ds. They are not making new specialized games for the Nintendo ds lite. they are still making games that fit both the original DS and the Nintendo DS Lite.
hell no
yes
yes they do
No why would you ask this?
Yes - All GBA games will fit into the DS or the DS Lite but won't in the DSi.(If you have a flashcard then it's 90% that you can't run GBA games on it.)
in which battery fit in samsung tab
Yes, regular DS games fit into a 3DS.
A DS Lite is about 4 inches wide, and 4 inches tall. They are small enough to fit in your palm.
no a samsung toccos are fatter than a samsung tocco lite
there is a slot
in ds lite and the regular one, yes.