You can take screenshots in Android using the Quick Settings menu. Open the menu and look for the Screenshot tile/icon. Tap it to open the feature and take your screenshot. You can also use a button combination on some Android devices to take a screenshot of the entire screen. The most common way is by holding both the Power and Volume Down buttons at the same time until your phone takes a screenshot.
You can also take scrolling screenshots and screenshots in incognito mode with a little extra work.