A PC case is the enclosure that houses the components of a personal computer. It protects vital parts like the motherboard, power supply, and hard drives from dust and physical damage. Cases come in various sizes, such as ATX and microATX, to accommodate different hardware configurations. In addition to protection, a PC case also aids in cooling by allowing airflow through vents and fans. Many cases feature design elements like tempered glass panels and RGB lighting, appealing to users who want a visually striking setup. Overall, the case is essential for both functionality and aesthetics in a computer system.