What is the difference between exponents and subscripts in math?

Answer 1

exponents (written as superscripts) indicate repeated multiplication, just as multiplication indicates repeated addition.

2^4 = 2*2*2*2 = 16

Subscripts are usually used to distinguish between elements of a set, such as

terms of a sequence: 1,3,5,7,9,...
T_n = 2n-1

Elements of a vector. If

v = <1,9,3> then
v₁=1
v₂=9
v₃=3