This document provides an introduction to computers including what a computer is, what it can do, its capabilities and limitations. It describes the basic parts of a computer system including hardware, software, data and users. It discusses the central processing unit, memory, input devices like keyboards and mice, output devices like monitors and printers, and storage devices like hard disks and floppy disks. It also provides an overview of computer software including operating systems and common application software like word processing, spreadsheets, presentations and databases.