$\quad$ I started learning $\textbf{Galois Cohomology}$ just 2 days ago and I am now confused with several conceptions. For example, there is a corollary written below.
$\quad$ $\textbf{Corollary}$: Let $\textbf{K}$ be a field of characteristic not dividing $n\geq1$, and suppose that $\textbf{K}$ contains the $n$th roots of unity. The Galois group of the maximal abelian extension of $\textbf{K}$ of exponent $n$ is Kummer dual to $\textbf{$K^{*}/K^{*n}$}$.
$\quad$ $\textbf{Here is my question}$: I know $\textbf{$K^{*}$}$ means the multiplicative group of $K$, but I am not sure what $K^{*n}$ means. In my opinion it means $\{x^{n}\mid x\in K^{*}\}$, and $K^{*}/K^{*n}$ means a quotient group, am I right? And could you give me a concrete example to make me understand it better?
$\quad$ $\textbf{I really appreciate your help.}$ That may seem easy to you, but really makes me confused.