Windows 10 has the ability to capture the entire screen as well as provides support for keyboard shortcuts to capture the screen from Win+PrintScreen buttons. All these screenshots are saved to the pictures library in Screenshots folder. In Windows 10 now it is possible to screenshot just a single screen or screenshot only the active Window.
Screenshot the Active Window
Windows provides the ability to create screenshots of the Active window using the hotkeys Alt+PrintScrn. The Alt+PrintScreen does not save the screenshot image unlike the Win+PrintScreen Button does.
It copies the image to the clipboard and you will be able to get the image by pasting it in a document as well as you can save the image by pasting it in the Paint app by using Ctrl+V and then saving it as any meaningful name. Similarly, you can also paste the image in any other app such as Word and use the simple paste command to use the image from the clipboard.
Windows 10 has a wide range of screenshot capturing tools so you will not need any additional 3rd party application to capture the screenshots.