Selection tools
There are several marquee tools you can use to create pixel selections:
Rectangular Marquee Tool—creates a rectangular or square selection.
Elliptical Marquee Tool—creates an elliptical or circular selection.
Column Marquee Tool—creates a rectangular selection of the set pixel width which spans the entire image's height.
Row Marquee Tool—creates a rectangular selection of the set pixel height which spans the entire image's width.