This report delves into the intricate world of computer systems, exploring their fundamental functions, design principles, construction techniques, and essential maintenance practices. It examines the role of computer systems in diverse environments, including education, healthcare, and banking, highlighting their transformative impact. The report further dissects the hardware, software, and peripheral components that constitute a computer system, providing a comprehensive understanding of their individual roles and interdependencies. It then delves into the process of designing computer systems, outlining system design specifications tailored to specific user needs and evaluating their suitability. The report concludes with a detailed exploration of building and configuring computer systems, encompassing both hardware assembly and software installation. It also emphasizes the importance of routine maintenance tasks, such as defragmentation, antivirus updates, and driver upgrades, to ensure optimal system performance and longevity.