What is the meaning of $\mathbb{F}_q^{\times}$?

Question

What is the meaning of $\mathbb{F}_q^{\times}$? I've never seen the $\times$ being used in superscript.

Answer 1

For any ring $R$, its common to use $R^\times$ to mean the multiplicative group of units.

Answer 2

It denotes the multiplicative group of the field, i.e. $(\Bbb F_q\setminus\{0\}, \cdot) $.