A computer case is a device that protects and contains the main components of a computer, such as the motherboard, processor, memory, graphics card and storage devices. Its main function is to provide physical protection and to enable cooling of the components through proper air circulation. The enclosures can vary in size and design, the most common sizes being ATX, Micro-ATX and Mini-ITX, with ATX providing the most space for the components. Material choices range from steel to aluminum and fiberglass composites, which affects the weight and durability of the chassis. Cooling solutions can include fans, passive coolers, or even liquid cooling systems to keep components at the optimal temperature. Expansion slots provide space for graphics cards, add-on cards and storage devices. Chassis can have a front panel with USB ports, audio connections and a power button. High-quality enclosures can include sound-absorbing materials to reduce noise from the computer's operation. Modular enclosures allow the user to customize the inside of the enclosure according to their needs. Finally, the design of the computer enclosure varies depending on the manufacturer and model, from minimalist, elegant options to more eye-catching designs that can include striking visual elements.

The choice of computer case is an individual decision that depends on the user's needs, budget and aesthetic preferences. A well-chosen case protects components, allows for efficient cooling and facilitates access to components for maintenance or upgrades.