When im using photoshop how can i cut a peace of picture from my main picture?

To cut a piece of a picture from your main picture in Photoshop, you can use the selection tools such as the Marquee tool, Lasso tool, or the Quick Selection tool to select the area you want to cut. Once you have made your selection, you can either press the Delete key on your keyboard to remove the selected area, or go to Edit > Cut in the menu bar. You can then paste the cut piece onto a new layer or document if desired.