Photoshop Marquee Select Tools
The marquee tools are selection tools which allow you to select rectangles, ellipses and 1-pixel rows and columns.
The marquee tools are located at the top left of the Photoshop Toolbox. Click and hold your mouse over the marquee tool to see the four options:
Make a rectangular selection. Hold the shift key down to constrain the selection to a square.
Note: ImageReady also allows rounded corners in rectangles.
Make an elliptical selection. Hold the shift key down to constrain the selection to a circle.
Single Row Marquee
Make a horizontal selection 1 pixel high.
Single Column Marquee
Make a vertical selection 1 pixel wide.
When you select any marquee tool, related options appear in the Tool Options bar (just below the main menu). This allows you to set the type of selection, feathering, etc. Options are slightly different for each marquee tool.