The Select toolbar provides tools that allow you to select parts of a photograph to fill, copy/paste, or delete.
If you copy a selection, you can paste it as a new overlay in the same (or different) project, or you can paste it into a new project. You can also delete a selected area. If the selection covers any visible part of an overlay image, only content from that overlay image will be deleted (so you can delete content from an overlay image without risk of deleting something from layers underneath it).
Keyboard Shortcuts
Rectangular Selection
The Rectangular Selection tool allows you to click the mouse button, drag, then release to create a rectangular selection in the photo. Hold the Ctrl key to make a square selection.

Oval Selection
The Oval Selection tool allows you to click the mouse button, drag, then release to create an oval selection in the photo. Hold the Ctrl key to make a circular selection.

Polygon Selection
The polygon selection tool allows you to create a polygonal selection. Click a point on the image and release the mouse to create the anchor point, then move the mouse to the second point and click again. Repeat as many times as needed to create the desired polygon, then close the polygon by clicking on the first anchor point or double clicking.

Free Form Selection
The free form selection tool allows you to select a hand-drawn region. Drag the cursor around the region you want to select, then release the mouse button to complete the selection.

Magnet Selection
The magnet selection tool allows you to select an object in your image by snapping to the object's edges. Start the selection by clicking on an object's edge. Then click anywhere within the circle displayed to add a segment to the selection outline. Continue adding segments until the whole object is outlined. Clicking on the first point or double clicking will complete the selection.

Magic Wand
The Magic Wand tool allows you to click on a single spot in the photo to select all adjacent areas of a similar color (click a point in the sky to select the entire sky, for example). When the Magic Wand tool is selected, you can specify a Tolerance value by clicking on the drop down arrow next to the button. This determines how similar a pixel's color must be to get selected.