A rack-mount computer case differs from traditional cases that stand on or under a desk. It is designed for mounting into a standardized frame, also known as a rack or a cabinet. This frame can be imagined as a tall metal cabinet with rails into which various devices, such as servers, network components, or audio equipment, are slid and screwed. The main distinguishing feature of a rack case is its standardized width, which is usually 19 inches, to fit perfectly into the aforementioned frame. The height is not given in centimeters, but in special units called "U" (Units). One U unit corresponds to approximately 4.45 cm. A computer case can thus have a size of, for example, 1U, 2U, or 4U, which determines how much vertical space it occupies in the rack. Thanks to this system, it is possible to efficiently organize a large amount of equipment on top of each other in a small space. Therefore, these cases are primarily used in professional environments, such as data centers or server rooms, where it is necessary to house multiple computers and other devices clearly and with the possibility of centralized cooling and cable management.