Once you release the mouse, the selected part of a screen will be copied to clipboard.
HOW TO TAKE A SCREENSHOT ON WINDOWS WINDOWS
A faster alternative is to press the keyboard combination Windows Key + Alt + PrtSc when Game Bar is active. In the menu that appears, click the Capture icon. You’ll see a red rectangle as you move the cursor. To start the screenshot process, press the Windows key + G on your keyboard to open the Game Bar. Press left click and drag to select a portion of the screen you want to shot. You get options like taking screenshots of scrolling windows, screenshots of particular colors on the screen, or even measuring the dimensions of objects in your screenshot using an on-screen ruler. The screen will become grayed out, and the cursor will turn to a white cross. PicPick is a third-party application that offers a large variety of screenshot-taking options along with some other tools as well that can be useful to you. Taking a Screenshot on Windows using PicPick It also calls out the small menu and you can then select the section you want to take on your computer screen.
Note: this shortcut only works if you are using Windows 10.