A computer case,
also known as a computer chassis, cabinet, tower, box, enclosure, housing
or simply case, is the enclosure that contains the main components of a
computer. A computer case is sometimes referred to metonymously as a CPU,
referring to the primary component housed within the case; this was a more
common term in the earlier days of home computers, when peripherals other
than the motherboard were usually housed in their own separate cases.
are usually constructed from steel, aluminum, or plastic, although other
materials such as wood, plexiglas, and Lego have also been used in case
can come in many different sizes, known as form factors. The size and shape
of a computer case is usually determined by the form factor of the motherboard,
since it is the largest component of most computers. Consequently, personal
computer form factors typically specify only the internal dimensions and
layout of the case. Form factors for rack-mounted and blade servers may
include precise external dimensions as well, since these cases must themselves
fit in specific enclosures.
a case designed for an ATX motherboard and power supply may take on several
external forms, such as a vertical tower or a flat desktop or pizza box.
Full-size computer tower cases are typically larger in volume than desktop
cases, with more room for drive bays and expansion slots. Desktop cases
and mini-tower cases, designed for the reduced microATX form factor, are
popular in business environments where space is at a premium.
the most popular form factor for desktop computers is ATX, although microATX
and small form factors have also become very popular for a variety of uses.
Companies like Shuttle Inc. and AOpen have popularized small cases, for
which FlexATX is the most common motherboard size. Apple Inc. has also produced
the Mac Mini computer, which is similar in size to a standard CD-ROM drive.
cases come in mini-tower, mid-tower, and big-tower or full-tower sizes.
Full tower cases are typically 30 inches or more in height and intended
to stand on the floor. They have anywhere from six to ten externally accessible
drive bays, with more bays only internally accessible. The ratio of external
to internal bays is shifting, however, as computing technology moves from
floppy disks and CD-ROMs to large capacity hard drives, USB flash drives,
and network-based solutions. Midtower PC cases are smaller, about 24" high
with two to four external bays. A minitower case will typically have only
one or two external bays and stand from 12" to 18" tall.