If you aren't deliberate and exact when operating your computer, you may engage a feature like its zoom function without meaning to. Alternately, if you're on a shared computer, another user may engage the zoom function to be able to read small print on the screen more clearly. Whatever the case, you need to know how to zoom out again to be able to use your computer as you want.
Hold down the key with the Windows logo on it if you are using a PC. If you are using a Mac, hold down the Command and Option keys.
Press the hyphen key -- also known as the minus key (-) -- while holding down the other key(s) to zoom out.
Hold the Control key on a Mac and scroll up or down using the mouse wheel to zoom in and out, if you prefer.