Mr. Charlie

Say you wanna look at the Andromeda galaxy, even under the darkest skies it's a faint object and tricky to locate. Ordinarily you'd locate the constellation Pegasus, look to it's upper left-most star, then go 3 constellation stars to the right, then go up around 2 degrees, then look slightly to the right, and the Andromeda galaxy will be in that area of the sky. Finding it with a powerful telescope is even more difficult because it focuses on a tiny area of the sky and so every movement is exagerated.

With a computerised system, you simply type in the number for the Andromeda galaxy on the key pad, and press Go To, and a few seconds later it's there in your eyepiece.