Need a litle help on how unity works

Hello.I am gona start using unity when ver 5 comes out but since i come from unrel engine 3 i wanted to ask about some of the most important rules(call it transition terminology) that the unity engine uses.Im gona post some of the most precise things that i use un unreal and hope that someone explains to me if this thing are the same as for the unity pipeline or not necessary.

unreal
1-when i make a normal map i have to invert the green chanel for the normal map to displayd correctly in...

Need a litle help on how unity works