This document classifies computers based on their size from largest to smallest: Super computers are the largest and most powerful, used for scientific modeling and simulation. Mainframe computers are large servers that enable many users to access resources simultaneously, used by large organizations for tasks like ATM transactions. Mini computers have processing power between mainframes and personal computers. Workstations are used for engineering and design applications requiring moderate computing power and graphics. Personal computers are the smallest and most affordable for individual use.