Computer case

The components housed inside the case (such as the CPU, motherboard, memory, mass storage devices, power supply unit and various expansion cards) are referred as the internal hardware, while hardware outside the case (typically cable-linked or plug-and-play devices such as the display, speakers, keyboard, mouse and USB flash drives) are known as peripherals.

The external case panels, at least one of which are removable, cover the chassis from the front, sides and top to shield the internal components from physical intrusion and dust collection, and are typically made from painted metallic and/or plastic material, while other materials such as mesh, tempered glass, acrylic, wood and even Lego bricks have appeared in many modern commercial or home-built cases.

Cases can come in many different sizes and shapes, which are usually determined by the form factor of the motherboard since it is physically the largest hardware component in most computers.

Form factors for rack-mounted and blade servers may include precise external dimensions as well since these cases must themselves fit in specific enclosures.

[2][3][4][5][6] Companies like In Win Development, Shuttle Inc. and AOpen originally popularized small cases, for which FlexATX was the most common[dubious – discuss] motherboard size.

As of 2010 Mini ITX has widely replaced FlexATX as the most common small form factor mainboard standard.

Hence, many full tower cases include locking doors and other physical security features to prevent theft of the discs.

[13] The marketing term midi-tower sometimes refers to cases smaller than mid-tower but larger than mini-tower, typically with two to three external bays.

[15] Computer cases usually include sheet metal enclosures for a power supply unit and drive bays, as well as a rear panel that can accommodate peripheral connectors protruding from the motherboard and expansion slots.

Looking front-to-back, accessing the motherboard, PSU, drive bays, and most case fan installation points are done by removing the left side panel.

From the early 2000s onwards there is a trend towards tool-less cases, in which components are held together with snap-in plastic rails, thumbscrews, and other methods that do not require tools; this facilitates quick assembly and modification of computer hardware and is also cheaper to manufacture.

Throughout the 1990s, most computer cases had simple rectangular shapes, and were often painted beige or white with little attention given to the visual design.

Beige box designs are still found on a large number of budget computers assembled from generic components.

Modded cases may also include colored internal lighting, custom paint, or liquid cooling systems.

[26] Prominent after-market case manufacturers include Antec, BitFenix, Cooler Master, Corsair, Fractal Design, In Win Development, Lian Li, NZXT Corp., Phanteks, Rosewill, and Thermaltake, (DIY PC) Some computer cases include a biased switch (push-button) which connects to the motherboard.

However, most such systems are quite simple in construction; a knowledgeable intruder can open the case or modify its contents without triggering the switch.