Square a a
Cube a a a
1
Looking at the square with side length a — what is the area of the square?
Area of square  =  a × a  =  a2
2
Looking at the cube with side length a — what is the volume of the cube?
Volume of cube  =  a × a × a  =  a3
Understanding Indices
Area of square  =  a × a  =  a2
where  a  is the base  &  2  is the index (power)
Volume of cube  =  a × a × a  =  a3
where  a  is the base  &  3  is the index (power)
∴   Indices tell us how many times a number
is multiplied by itself.