How can we crop an image in the Photoshop?

there is a dedicated Crop tool in Tools Panel for cropping

particular image croping in ( Toolbox - crop tool ( ctr IC)

We can crop image by using a Crop Tool 

Press ( C ) and select what you want to crop

on the left side tool bar you can select a crop tool and select the area to which you want to crop, or else just select marquee tool or draw the area which you want to crop and press c for crop then press enter and enter again tadddaaaaa... you just cropped the area :)