of course u can
No but you can play Gameboy Advance games on a original Nintendo DS and a Nintendo DS Lite.
No, the Nintendo DS lite cannot play 3DS games.
The original DS can play them, as can the DS lite. The DSi, DSi XL and the 3DS do not have a GBA slot.
Yes, the NDS lite can play all DS games
Yes you can play Nintendo DS games on a Nintendo ds lite.
The Nintendo DSi has internet (thus the 'i'), a larger screen, and other features the DS does not have, as well as a camera on both the inside and the outside, whereas the DS Lite has neither.
No. But, you will be able to play ds lite games ont the 3DS.
No. There is no way to download or play DSiWare games on Nintendo DS or DS Lite systems.
Yes, DS games are region free.
It can play GameBoy games and DS games.
There is no such thing as a DS Lite game they are all just DS games. So, yes, you can play them on the old DS.
You can't download games for DS lite because you need a game cartridge for the console.