Use a tool

Do one of the following:

Click a tool in the Tools panel. If there is a small triangle at a tool’s lower right corner, hold down the mouse button to view the hidden tools. Then click the tool you want to select.
Press the tool’s keyboard shortcut. The keyboard shortcut is displayed in its tool tip. For example, you can select the Move tool by pressing the V key.

Pressing and holding a keyboard shortcut key lets you temporarily switch to a tool. When you let go of the shortcut key, Photoshop returns to the tool you were using before the temporary switch.

Using the selecting tools

A.: Tools panel
B.: Active tool
C.: Hidden tools
D.: Tool name
E.: Tool shortcut
F.: Hidden tool triangle