This report provides a comprehensive overview of computer systems, covering their roles in various environments like hospitals, education, transport, gaming, and hotels. It details the hardware, software, and peripheral components of a computer system, including the CPU, storage devices, operating systems, application programs, and input/output devices. A comparison of different types of computer systems, such as microcomputers, minicomputers, mainframe computers, and supercomputers, is presented. The report also includes a system design specification tailored to a client's needs, along with an evaluation of its suitability. Furthermore, it describes the process of building and configuring a computer system to meet a specific design, including safety precautions, component installation, and software setup. The report concludes with routine maintenance tasks, such as physical cleaning, data backup, disk defragmentation, web history clearing, antivirus updates, and system service management, as well as hardware and software upgrades for performance enhancement. This document is available on Desklib, a platform offering AI-powered study tools and a wide array of student resources.