What is the meaning of (Math.Pow) , (Math.ciel) , (Math.pi)?

Question

i found a lot of answer bud i really don't get the right one..

Answer 1

Math.pow(2,3)-->2^3
Math.ceil(2.53)-->3
Math.floor(2.53)-->2
Math.PI-->3.1415,,,

Answer 2

thanks a lot bro..