[Hardware
Hanne Rylaarsdam
Computer hardware comprises the physical parts of a computer, such as the central processing unit (CPU), random access memory (RAM), motherboard, computer data storage, graphics card, sound card, and computer case. It includes external devices such as a monitor, mouse, keyboard, and speakers.[1][2]
By contrast, software is the set of instructions that can be stored and run by hardware. Hardware is so-termed because it is hard or rigid with respect to changes, whereas software is soft because it is easy to change.
Hardware is typically directed by the software to execute any command or instruction. A combination of hardware and software forms a usable computing system, although other systems exist with only hardware.
The template for all modern computers is the Von Neumann architecture, detailed in a 1945 paper by Hungarian mathematician John von Neumann. The paper describes a design architecture for an electronic digital computer with subdivisions of a processing unit consisting of an arithmetic logic unit and processor registers, a control unit containing an instruction register and program counter, a memory to store both data and instructions, external mass storage, and input and output mechanisms.[3] The meaning of the term has evolved to mean a stored-program computer in which an instruction fetch and a data operation cannot occur at the same time because they share a common bus. This is referred to as the Von Neumann bottleneck and often limits the performance of the system.[4]
The personal computer is one of the most common types of computer due to its versatility and relatively low price. Desktop personal computers have a monitor, a keyboard, a mouse, and a computer case. The computer case holds the motherboard, fixed or removable disk drives for data storage, the power supply, and may contain other peripheral devices such as modems or network interfaces. Some models of desktop computers integrated the monitor and keyboard into the same case as the processor and power supply. Separating the elements allows the user to arrange the components in a pleasing, comfortable array, at the cost of managing power and data cables between them.
Laptops are designed for portability but operate similarly to desktop PCs.[5] They may use lower-power or reduced size components, with lower performance than a similarly priced desktop computer.[6] Laptops contain the keyboard, display, and processor in one case. The monitor in the folding upper cover of the case can be closed for transportation, to protect the screen and keyboard. Instead of a mouse, laptops may have a touchpad or pointing stick.
Some tablets include fold-out keyboards or offer connections to separate external keyboards. Some models of laptop computers have a detachable keyboard, which allows the system to be configured as a touch-screen tablet. They are sometimes called "2-in-1 detachable laptops" or "tablet-laptop hybrids".[7]
A computer case encloses most of the components of a desktop computer system. It provides mechanical support and protection for internal elements such as the motherboard, disk drives, and power supply, and controls and directs the flow of cooling air over internal components. The case is also part of the system to control electromagnetic interference radiated by the computer and protects internal parts from electrostatic discharge. Large tower cases provide space for multiple disk drives or other peripherals and usually stand on the floor, while desktop cases provide less expansion room. All-in-one style designs include a video display built into the same case. Portable and laptop computers require cases that provide impact protection for the unit. Hobbyists may decorate the cases with colored lights, paint, or other features, in an activity called case modding.
An expansion card in computing is a printed circuit board that can be inserted into an expansion slot of a computer motherboard or backplane to add functionality to a computer system via the expansion bus. Expansion cards can be used to obtain or expand on features not offered by the motherboard.
A storage device is computer hardware or digital media that is used for storing, porting, and extracting data files and objects. It can hold and store information either temporarily or permanently and can be internal or external to a computer. Data storage is a core function and fundamental component of computers. Dedicated storage devices include RAIDs and tape libraries.
Data is stored by a computer using a variety of media. Hard disk drives (HDDs) are found in virtually all older computers, due to their high capacity and low cost, but solid-state drives (SSDs) are faster and more power efficient, although currently more expensive than hard drives in terms of dollar per gigabyte,[11] so are often found in personal computers built post-2007.[12] SSDs use flash memory, which stores data on MOS memory chips consisting of floating-gate MOSFET memory cells. Some systems may use a disk array controller for greater performance or reliability.
To transfer data between computers, an external flash memory device (such as a memory card or USB flash drive) or optical disc (such as a CD-ROM, DVD-ROM or BD-ROM) may be used. Their usefulness depends on being readable by other systems; the majority of machines have an optical disk drive (ODD), and virtually all have at least one Universal Serial Bus (USB) port. USB sticks are typically pre-formatted with the FAT32 file system, which is widely supported across operating systems.
Input devices allow the user to enter information into the system, or control its operation. Most personal computers have a mouse and keyboard, but laptop systems typically use a touchpad instead of a mouse. Other input devices include webcams, microphones, joysticks, and image scanners.
Output devices are designed around the senses of human beings. For example, monitors display text that can be read, speakers produce sound that can be heard.[13] Such devices also could include printers or a Braille embosser.
A mainframe computer is a much larger computer that typically fills a room and may cost many hundreds or thousands of times as much as a personal computer. They are designed to perform large numbers of calculations for governments and large enterprises.
In the 1960s and 1970s, more and more departments started to use cheaper and dedicated systems for specific purposes like process control and laboratory automation. A minicomputer, or colloquially mini, is a class of smaller computers that was developed in the mid-1960s[14][15] and sold for much less than mainframe[16] and mid-size computers from IBM and its direct competitors.
A supercomputer is superficially similar to a mainframe but is instead intended for extremely demanding computational tasks. As of November 2021[update], the fastest supercomputer on the TOP500 supercomputer list is Fugaku, in Japan, with a LINPACK benchmark score of 415 PFLOPS, superseding the second fastest, Summit, in the United States, by around 294 PFLOPS.
The term supercomputer does not refer to a specific technology. Rather it indicates the fastest computations available at any given time. In mid-2011, the fastest supercomputers boasted speeds exceeding one petaflop, or 1 quadrillion (10^15 or 1,000 trillion) floating-point operations per second.Supercomputers are fast but extremely costly, so they are generally used by large organizations to execute computationally demanding tasks involving large data sets. Supercomputers typically run military and scientific applications. Although costly, they are also being used for commercial applications where huge amounts of data must be analyzed. For example, large banks employ supercomputers to calculate the risks and returns of various investment strategies, and healthcare organizations use them to analyze giant databases of patient data to determine optimal treatments for various diseases and problems incurring to the country.
When using computer hardware, an upgrade means adding new or additional hardware to a computer that improves its performance, increases its capacity, or adds new features. For example, a user could perform a hardware upgrade to replace the hard drive with a faster one or a solid-state drive (SSD) to get a boost in performance. The user may also install more random-access memory (RAM) so the computer can store additional temporary data, or retrieve such data at a faster rate. The user may add a USB 3.0 expansion card to fully use USB 3.0 devices, or could upgrade the graphics processing unit (GPU) for cleaner, more advanced graphics, or more monitors. Performing such hardware upgrades may be necessary for aged computers to meet a new, or updated program's system requirements.
In large organizations, hardware upgrades are handled by administrators who are also in charge of keeping networks running smoothly. They replace network devices like servers, routers and storage devices based on new demands and capacities.
Because computer parts contain hazardous materials, there is a growing movement to recycle old and outdated parts.[18] Computer hardware contain dangerous chemicals such as lead, mercury, nickel, and cadmium. According to the EPA these e-wastes have a harmful effect on the environment unless they are disposed of properly. Making hardware requires energy, and recycling parts will reduce air pollution, water pollution, as well as greenhouse gas emissions.[19] Disposing unauthorized computer equipment is in fact illegal. Legislation makes it mandatory to recycle computers through the government approved facilities. Recycling a computer can be made easier by taking out certain reusable parts. For example, the RAM, DVD drive, the graphics card, hard drive or SSD, and other similar removable parts can be reused.
Many materials used in computer hardware can be recovered by recycling for use in future production. Reuse of tin, silicon, iron, aluminum, and a variety of plastics that are present in bulk in computers or other electronics can reduce the costs of constructing new systems. Components frequently contain copper, gold, tantalum,[20][21] silver, platinum, palladium, and lead as well as other valuable materials suitable for reclamation.[22][23]
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