The Magnetic Selection tool is used to trace selections around objects and areas in images as it snaps to any contours or edges.
Choose the Magnetic Selection tool by doing one of the following:
Tip: You can cycle through Magnetic, Free, and Polygonal selection tools by pressing+ on your keyboard.
In the Tool Options pane, customize the options for the Magnetic Selection tool:
Click in your image to add anchor points and guide your selection around the object or area you'd like to select. To reselect an anchor point, click the last added point to remove it, then click to add a new anchor point.
To complete your selection, click the first anchor point or press thekey.