Screenshots are pictures of your computer screen. Taking a screenshot on your Mac computer requires keyboard shortcuts, (pressing certain keys at the same time), and there are a few different types of screenshots that can be taken through keyboard shortcuts.

• Command + Shift + 3, takes a screen shot of the entire display, i.e. the entire screen. 
• Command + Shift + 4, takes a screenshot of an area that you can choose. 
• Command + Shift + 4 + Spacebar, takes a screen shot of a selected window

1. To take a screenshot of your entire screen, open up what you want to take a screenshot of, in this case it was the desktop background. Then press Command + Shift + 3.
   
    
2. Then an icon of the image will appear on your desktop of the image you have just taken.
   

1. To take a screenshot of a portion of the screen use the keyboard shortcut Command + Shift + 4.
   
    
2. Once you have pressed the aforementioned keyboard shortcut, a small cross will appear in place of the mouse. Click and hold, then drag the area you wish to take a screenshot of. Once you release the mouse click it will take a screenshot. Below is an example.
   
    
3. Once you have taken the screenshot the image will appear on your desktop, the same as previously.
   
    
4. To take a screenshot of a selected window, open the selected window and hover the mouse over it and hold, Command + Shift + 4 + Spacebar, the window that will have its picture taken will darken. Release Command + Shift + 4 + Spacebar, and the image will appear on your desktop similar to before.