Lesson 1: What is a Computer? Definition: A computer is an electronic device that accepts data (input), processes it, stores it, and gives meaningful output. It performs arithmetic and logical operations quickly and accurately. Evolution: Early computers were large, slow, and expensive. Examples include: ENIAC, UNIVAC. Modern computers are faster, smaller, and more affordable (laptops, smartphones, etc.) Purpose: To make work faster, more accurate, and more efficient — in education, business, science, communication, and entertainment.