Not sure, but casual is more xp, more gold, easier.

don't play casual until you're good enough to go pubstomping
bad to learn on it

so normal untill i get good?

well yeah, but it's not like you play casual once you get good
casual is just another set of stats and another set of bad players you can farm coins off of

in casual mode, denying doesnt do anything. they still get full xp. also every hero kill is about 500 gold instead of the normal 250.
If someone has an IMMORTAL streak and u kkill him, u can get like almost 2k gold right there assists also give u much more gold so pretty much, u get more gold from ganking and killing heroes rather than farming creeps

so i hear. and people die very easy but then again low respawn xD

denying works in casual mode, if you deny the creep out of experience range, they still get no experience (ie plague rider)

well any creep getting killed out of range gives you no experience
i meant like if they are in range .

also you dont lose gold when u die in CM

they would make it free 2 days after i bought a new account