机箱是计算机大部分部件的载体，一般不包括显示器、键盘、鼠标。机箱有时被错误地作为中央处理器、主板等机箱内部组件的总称。

Cooler Master 690 II Advanced Nvidia Edition mid tower case

A beige mini tower case (microATX form factor)

Micro ATX Desktop case beside standard ATX tower case

Enthusiast case featuring translucent panel casemod

A computer case also known as a computer chassis, tower, system unit, cabinet, base unit or simply case is the enclosure that contains most of the components of a computer (usually excluding the display, keyboard and mouse).

Cases are usually constructed from steel (often SECC — Steel, electrogalvanized, cold-rolled, coil) or aluminium. Plastic is sometimes used, and other materials such as glass, wood and even Lego blocks have appeared in home-built cases.