what is ^?

^ means power,
e.g. 2^5 = 2 * 2 * 2 * 2 * 2
y^2 = y * y

One usage of this symbol ^ in maths is to represent a logical conjunction AND. For example, if there are two statements A and B, then the result of A^B will be:
A B A^B
true true true
true false false
false true false
false false false

When it appears in vector calculation, A ^ B means a wedge product of A and B. So it varies and depends on the subject that you mentioned.