A computer differs from a calculator in that calculators are used mainly for computations, whereas computers are used for a wide range of things, from communicating with someone half way around the world to playing solitaire. Its main function is to calculate. It is faster and more powerful than a calculator. The computer can perform more than just calculations, it can play, synthesize, and write it's own music. The evolved calculator.
Calculators have small screens and everything else attached.
A computer is a machine that can make your life easier. A person invented the computer. A massive computer can be as big as this classroom. The computer does many different jobs, as where the calculator does mostly math functions. Most functions of the calculator are the same speed, whereas the computer can vary in.