A desktop computer is a personal computer designed primarily for use at a fixed workstation rather than being carried regularly between locations. A conventional desktop system commonly consists of a separate computer case, monitor, keyboard and mouse, although all-in-one desktop computers integrate the display and computing hardware into a single enclosure. Desktop computers generally receive power from mains electricity and do not depend on a built-in battery for ordinary operation.
Their larger physical size compared with laptops allows manufacturers to provide substantial cooling, larger power supplies, multiple storage devices and expansion components. Desktop computers are used in homes, offices, schools, creative studios, laboratories, gaming environments and many other settings where portability is less important than performance, ergonomics, expandability or cost.
A conventional desktop's computer case contains the core hardware. It normally includes a motherboard, CPU, RAM, storage, power supply and cooling system, and it may contain a discrete graphics card and additional expansion devices. The case provides physical protection and airflow while allowing access to components for installation or maintenance. Different case formats, such as full towers, mid-towers and compact systems, provide different amounts of internal space.
Larger cases can accommodate more drives, expansion cards and cooling equipment, although physical size does not directly determine performance. Some small desktop systems use highly integrated designs similar to laptops and therefore provide less internal expansion. Desktop computing consequently describes a form factor and intended usage pattern rather than one specific internal architecture.
Desktop computers are often more expandable than laptops. Depending on the design, users can replace or add RAM, storage devices, graphics cards, expansion cards, cooling components and other hardware. This modularity can extend the useful life of a system and allow it to be configured for particular workloads. A workstation used for video production may have substantial RAM, fast storage and a powerful GPU, while an office desktop may require considerably less graphics capability. Gaming desktops commonly use high-performance processors and discrete graphics cards. The ability to upgrade components can be valuable because different workloads place different demands on hardware. However, compatibility constraints still apply, including motherboard interfaces, power-supply capacity, physical dimensions, firmware support and cooling requirements.
Desktop computers can provide substantial performance because they generally have fewer constraints on physical space and battery consumption than portable computers. A desktop can use a larger cooling system and a higher-capacity power supply, allowing high-performance processors and graphics hardware to operate within appropriate thermal limits. Continuous mains power also eliminates the need to prioritise battery life. High-end workstations can contain multiple GPUs, large amounts of memory and multiple storage devices, although such systems can consume considerable electricity and generate significant heat and noise. Performance is therefore achieved partly through the ability to provide physical resources that would be difficult to accommodate in a thin portable chassis.
A desktop computer usually uses an external monitor, which can provide a larger display and more ergonomic positioning than the integrated screen of a laptop. Users can select monitors according to resolution, refresh rate, colour characteristics, size and connectivity. Separate keyboards and mice can similarly be selected according to ergonomic or professional requirements. This separation can be advantageous in long-duration office, creative or gaming environments because the position of the screen and input devices can be adjusted independently. All-in-one computers reduce the number of separate components by integrating the display and computer into one enclosure, but they may provide less upgradeability than conventional tower systems because of their compact internal design.
Desktop computers are used for a broad range of workloads. Office users may run productivity software, web applications and communication tools. Creative professionals may use demanding applications for video editing, 3D modelling, photography, music production or engineering. Researchers may use desktops for programming, data analysis and scientific computation. Gamers may use systems with powerful graphics processors to render complex real-time environments. Businesses may deploy desktop systems in fixed workstations where employees do not need to move their computers. Specialist desktop systems can also operate as local servers or workstations for technical applications. The defining feature is therefore not the type of software used but the fixed, workstation-oriented form factor.
Desktop computers have advantages and disadvantages relative to portable systems. Their advantages can include upgradeability, repairability, high performance, larger displays, extensive peripheral connectivity and potentially better performance per unit cost for equivalent components. Their disadvantages include lack of portability, dependence on a fixed power source and the physical space required for separate components. A desktop cannot normally provide the same immediate mobility as a laptop, although remote-access software can allow users to control a desktop from other devices. Desktop systems can also be easier to maintain because components are often accessible, but this varies substantially with design.
The desktop computer remains an important category despite the growth of laptops, smartphones and tablets. It is particularly relevant where users require sustained performance, multiple displays, specialised peripherals, substantial storage, component upgrades or fixed workstation ergonomics. Modern desktop systems may be conventional tower PCs, compact mini PCs or all-in-one machines, so the category includes considerable variation. A desktop is therefore best defined by its intended fixed-location use and physical configuration rather than by a particular operating system or processor type. It can run Windows, Linux and other operating systems and can use processors based on different architectures. Its principal distinction from a laptop is that the computer is designed around a stationary workstation rather than portability, battery operation and tight physical integration.
