Others modify selection tools found in the toolbar. Photoshop also has a Select drop-down menu.
The Select and Mask button will create a masking layer using your selection (Option + Ctrl or ⌘R). Clicking the anti-aliasing box smooths the edges. Options also include settings for thickening or feathering of the border. The fourth, overlapping squares, keeps only the area shared by the new and previous selections. You can also subtract by holding the option key and making a new selection. The third, a filled and an empty square, subtracts the new selection from the previous.
The second, overlapping squares, adds to previous selections. The first, a square, draws a new selection each time. Options often include a set of icons describing how new selections will interact with existing ones. When you choose a selection tool, more options appear across the top of the workspace. Many of the selection tools in Photoshop are on the toolbar nested with similar tools.
