\documentclass{article}
\usepackage{latexsym}
\usepackage{amssymb}
\usepackage{amsmath}
\usepackage{mathtools}

\begin{document}
\[
\begin{array}{lcc}
\mbox{Bracket:} & \overbracket{abc\cdots xyz}& \underbracket{abc\cdots xyz}\\
\mbox{ Brace:} & \overbrace{abc\cdots xyz}& \underbrace{abc\cdots xyz}
\end{array}
\]
\end{document}
