The Crop Tool
"Cropping" is the process of removing portions of an image to create focus or strengthen the composition. You can crop an image using the Crop tool (C) or by going to Image > Crop. You can also trim pixels by going to Image > Trim.
Cropping an Image
Start with an image you wish to crop:
With the Crop tool selected, click and drag with the mouse to create a box in your picture over the portion of the picture you want to keep:
Once you have selected the part of the image you want to keep, press
(Windows) or (Mac OS), click the Commit button in the toolbar, or double-click inside the cropping marquee.
To accomplish this task with the Crop command in the Image menu, make a selection with the Marquee tool and then choose Image > Crop.