Computer hardware - Wikipedia Computer hardware PDP - 11 CPU board Computer hardware includes the physical, tangible parts or components of a computer, such as the central processing unit, monitor, keyboard, computer data storage, graphic card, sound card, speakers and motherboard. By contrast, software is instructions that can be stored and run by hardware. Hardware is so - termed because it is `` hard '' or rigid with respect to changes or modifications ; whereas software is `` soft '' because it can be easily updated or changed. Intermediate between software and hardware is `` firmware '', which is software that is strongly coupled to the particular hardware of a computer system and thus the most difficult to change but also among the most stable with respect to consistency of interface. The progression from levels of `` hardness '' to `` softness '' in computer systems parallels a progression of layers of abstraction in computing. 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 components. Contents 1 Von Neumann architecture 2 Types of computer systems 2.1 Personal computer 2.1. 1 Case 2.1. 2 Power supply 2.1. 3 Motherboard 2.1. 4 Expansion cards 2.1. 5 Storage devices 2.1. 5.1 Fixed media 2.1. 5.2 Removable media 2.1. 6 Input and output peripherals 2.1. 6.1 Input 2.1. 6.2 Output device 2.2 Mainframe computer 2.3 Departmental computing 2.4 Supercomputer 3 Hardware upgrade 4 Sales 5 Recycling 5.1 Toxic computer components 5.2 Environmental effects 5.3 National services 6 See also 7 Sources 8 External links Von Neumann architecture Main articles : Von Neumann architecture and Stored - program computer Von Neumann architecture scheme The template for all modern computers is the Von Neumann architecture, detailed in a 1945 paper by Hungarian mathematician John von Neumann. This 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. The meaning of the term has evolved to mean a stored - program computer in which an instruction fetch and a data operation can not 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. Types of computer systems Personal computer Basic hardware components of a modern personal computer, including a monitor, a motherboard, a CPU, a RAM, two expansion cards, a power supply, an optical disc drive, a hard disk drive, a keyboard and a mouse Inside a custom - built computer : power supply at the bottom has its own cooling fan The personal computer, also known as the PC, is one of the most common types of computer due to its versatility and relatively low price. Laptops are generally very similar, although they may use lower - power or reduced size components, thus lower performance. Case Main article : Computer case The computer case encloses most of the components of the system. It provides mechanical support and protection for internal elements such as the motherboard, disk drives, and power supplies, 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 extra internal 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 from Apple, namely the iMac, and similar types, include a video display built into the same case. Portable and laptop computers require cases that provide impact protection for the unit. A current development in laptop computers is a detachable keyboard, which allows the system to be configured as a touch - screen tablet. Hobbyists may decorate the cases with colored lights, paint, or other features, in an activity called case modding. Power supply Main article : Power supply unit A power supply unit ( PSU ) converts alternating current ( AC ) electric power to low - voltage DC power for the internal components of the computer. Laptops are capable of running from a built - in battery, normally for a period of hours. Motherboard Main article : Motherboard The motherboard is the main component of a computer. It is a board with integrated circuitry that connects the other parts of the computer including the CPU, the RAM, the disk drives ( CD, DVD, hard disk, or any others ) as well as any peripherals connected via the ports or the expansion slots. Components directly attached to or to part of the motherboard include : The CPU ( central processing unit ), which performs most of the calculations which enable a computer to function, and is sometimes referred to as the brain of the computer. It is usually cooled by a heatsink and fan, or water - cooling system. Most newer CPUs include an on - die graphics processing unit ( GPU ). The clock speed of CPUs governs how fast it executes instructions, and is measured in GHz ; typical values lie between 1 GHz and 5 GHz. Many modern computers have the option to overclock the CPU which enhances performance at the expense of greater thermal output and thus a need for improved cooling. The chipset, which includes the north bridge, mediates communication between the CPU and the other components of the system, including main memory. Random - access memory ( RAM ), which stores the code and data that are being actively accessed by the CPU. For example, when a web browser is opened on the computer it takes up memory ; this is stored in the RAM until the web browser is closed. RAM usually comes on DIMMs in the sizes 2GB, 4GB, and 8GB, but can be much larger. Read - only memory ( ROM ), which stores the BIOS that runs when the computer is powered on or otherwise begins execution, a process known as Bootstrapping, or `` booting '' or `` booting up ''. The BIOS ( Basic Input Output System ) includes boot firmware and power management firmware. Newer motherboards use Unified Extensible Firmware Interface ( UEFI ) instead of BIOS. Buses that connect the CPU to various internal components and to expand cards for graphics and sound. The CMOS battery, which powers the memory for date and time in the BIOS chip. This battery is generally a watch battery. The video card ( also known as the graphics card ), which processes computer graphics. More powerful graphics cards are better suited to handle strenuous tasks, such as playing intensive video games. Expansion cards Main article : Expansion card 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. Expansions cards can be used to obtain or expand on features not offered by the motherboard. Storage devices Main article : Computer data storage A storage device is any computing hardware and digital media that is used for storing, porting and extracting data files and objects. It can hold and store information both temporarily and permanently, and can be internal or external to a computer, server or any similar computing device. Data storage is a core function and fundamental component of computers. Fixed media Data is stored by a computer using a variety of media. Hard disk drives are found in virtually all older computers, due to their high capacity and low cost, but solid - state drives are faster and more power efficient, although currently more expensive than hard drives in terms of dollar per gigabyte, so are often found in personal computers built post-2007. Some systems may use a disk array controller for greater performance or reliability. Removable media To transfer data between computers, a USB flash drive or optical disc may be used. Their usefulness depends on being readable by other systems ; the majority of machines have an optical disk drive, and virtually all have at least one USB port. Input and output peripherals Main article : Peripheral Input and output devices are typically housed externally to the main computer chassis. The following are either standard or very common to many computer systems. Input 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 device Output devices display information in a human readable form. Such devices could include printers, speakers, monitors or a Braille embosser. Mainframe computer Main article : Mainframe Computer 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. An IBM System z9 mainframe Departmental computing Main article : Minicomputer 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. Supercomputer Main article : Supercomputer A supercomputer is superficially similar to a mainframe, but is instead intended for extremely demanding computational tasks. As of June 2018, the fastest supercomputer on the TOP500 supercomputer list is the Summit, in the United States, with a LINPACK benchmark score of 122.3 PFLOPS, exceeding the previous record holder, Sunway TaihuLight, by around 29 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. This section needs expansion with : mobile phone, cloud computing, embedded system and internet of things hardware ; systems on chip more generally. You can help by adding to it. ( October 2018 ) Hardware upgrade When using computer hardware, an upgrade means adding new hardware to a computer that improves its performance, adds capacity or new features. For example, a user could perform a hardware upgrade to replace the hard drive with a SSD to get a boost in performance or increase the amount of files that may be stored. Also, the user could increase the RAM so the computer may run more smoothly. The user could add a USB 3.0 expansion card in order to fully use USB 3.0 devices, or could upgrade the GPU for extra rendering power. Performing such hardware upgrades may be necessary for older computers to meet a programs ' system requirements. Sales This section needs to be updated. Please update this article to reflect recent events or newly available information. ( September 2018 ) For the third consecutive year, U.S. business - to - business channel sales ( sales through distributors and commercial resellers ) increased, ending up in 2013 at nearly 6 percent at $61.7 billion. The growth was the fastest sales increase since the end of the recession. Sales growth accelerated in the second half of the year peaking in fourth quarter with a 6.9 percent increase over the fourth quarter of 2012. Recycling Main article : Computer recycling Because computer parts contain hazardous materials, there is a growing movement to recycle old and outdated parts. 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. 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. Toxic computer components The central processing unit contains many toxic materials. It contains lead and chromium in the metal plates. Resistors, semi-conductors, infrared detectors, stabilizers, cables, and wires contain cadmium. The circuit boards in a computer contain mercury, and chromium. When these types of materials, and chemicals are disposed improperly will become hazardous for the environment. Environmental effects According to the United States Environmental Protection Agency only around 15 % of the e-waste actually is recycled. When e-waste byproducts leach into ground water, are burned, or get mishandled during recycling, it causes harm. Health problems associated with such toxins include impaired mental development, cancer, and damage to the lungs, liver, and kidneys. That 's why even wires have to be recycled. Different companies have different techniques to recycle a wire. The most popular one is the grinder that separates the copper wires from the plastic / rubber casing. When the processes is done there are two different piles left ; one containing the copper powder, and the other containing plastic / rubber pieces. Computer monitors, mice, and keyboards all have a similar way of being recycled. For example, first each of the parts are taken apart then all of the inner parts get separated and placed into its own bin. National services Recycling a computer is made easier by a few of the national services, such as Dell and Apple. Both companies will take back the computer of their make or any other make. Otherwise a computer can be donated to Computer Aid International which is an organization that recycles and refurbishes old computers for hospitals, schools, universities, etc. See also Information technology portal Computer architecture Electronic hardware Glossary of computer hardware terms History of computing hardware List of computer hardware manufacturers Open - source computing hardware Sources Jump up ^ `` Parts of computer ''. Microsoft. Archived from the original on 27 November 2013. Retrieved 5 December 2013. Jump up ^ von Neumann, John ( 1945 ). `` First Draft of a Report on the EDVAC '' ( PDF ). Archived ( PDF ) from the original on 9 August 2013. Jump up ^ Markgraf, Joey D. ( 2007 ). `` The Von Neumann bottleneck ''. Archived from the original on 9 June 2011. Retrieved 24 August 2011. Jump up ^ `` How long should a laptop battery last ? ''. Computer Hope. Archived from the original on 21 December 2013. Retrieved 9 December 2013. Jump up ^ Domingo, Joel. `` SSD vs. HDD : What 's the Difference ? ''. PCMag. Archived from the original on 19 March 2017. Retrieved 24 March 2017. Jump up ^ Edwards, Benj. `` Evolution of the Solid - State Drive ''. PCWorld. Archived from the original on 25 March 2017. Retrieved 24 March 2017. Jump up ^ `` US B2B Channel sales reach nearly $62 Billion in 2013, According to The NPD Group ''. NPD Group. 4 February 2014. Archived from the original on 8 August 2014. Jump up ^ `` How to recycle your old computer ''. Digital Trends. 18 December 2016. Archived from the original on 17 April 2017. Retrieved 18 April 2017. Jump up ^ Inc, Chris Keenan - Newtech Recycling. `` Newtech Recycling Specializes in Computer Disposal, Laptop Disposal, Desktop Disposal Mainframe Disposal and Server Disposal ''. www.newtechrecycling.com. Archived from the original on 29 March 2017. Retrieved 18 April 2017. Jump up ^ `` The Toxic Components of Computers and Monitors ''. Archived from the original on 27 April 2017. Retrieved 26 April 2017. Jump up ^ `` What 's Going On with Electronic Waste ? -- Electronics TakeBack Coalition ''. Archived from the original on 27 April 2017. Retrieved 26 April 2017. Jump up ^ `` Wire Recycling ''. All-Recycling-Facts.com. Archived from the original on 10 July 2017. Retrieved 5 May 2017. Jump up ^ `` Computer equipment recycling -- Essential Guide ''. ComputerWeekly. Archived from the original on 21 December 2016. Retrieved 8 May 2017. Jump up ^ Schofield, Jack ( 19 February 2015 ). `` How can I safely recycle my old PCs ? ''. The Guardian. ISSN 0261 - 3077. Archived from the original on 27 April 2017. Retrieved 26 April 2017. External links Media related to Computer hardware at Wikimedia Commons Learning materials related to Computer hardware at Wikiversity Basic computer components Input devices Keyboard Image scanner Microphone Pointing device Graphics tablet Joystick Light pen Mouse Optical Pointing stick Touchpad Touchscreen Trackball Refreshable braille display Sound card Webcam Softcam Video card Output devices Monitor Refreshable braille display Printer Speakers Plotter Sound card Video card Removable data storage Optical disc CD DVD Blu - ray Disk pack Floppy disk Memory card USB flash drive Computer case Central processing unit ( CPU ) HDD / SSD / SSHD Motherboard Network interface controller Power supply Random - access memory ( RAM ) Fax modem Expansion card Ports Ethernet FireWire ( IEEE 1394 ) Parallel port Serial port PS / 2 port USB Thunderbolt DisplayPort / HDMI / DVI / VGA eSATA Audio jack Major fields of computer science Note : This template roughly follows the 2012 ACM Computing Classification System. Hardware Printed circuit board Peripheral Integrated circuit Very - large - scale integration Systems on Chip ( SoCs ) Energy consumption ( Green computing ) Electronic design automation Hardware acceleration Computer systems organization Computer architecture Embedded system Real - time computing Dependability Networks Network architecture Network protocol Network components Network scheduler Network performance evaluation Network service Software organization Interpreter Middleware Virtual machine Operating system Software quality Software notations and tools Programming paradigm Programming language Compiler Domain - specific language Modeling language Software framework Integrated development environment Software configuration management Software library Software repository Software development Software development process Requirements analysis Software design Software construction Software deployment Software maintenance Programming team Open - source model Theory of computation Model of computation Formal language Automata theory Computational complexity theory Logic Semantics Algorithms Algorithm design Analysis of algorithms Algorithmic efficiency Randomized algorithm Computational geometry Mathematics of computing Discrete mathematics Probability Statistics Mathematical software Information theory Mathematical analysis Numerical analysis Information systems Database management system Information storage systems Enterprise information system Social information systems Geographic information system Decision support system Process control system Multimedia information system Data mining Digital library Computing platform Digital marketing World Wide Web Information retrieval Security Cryptography Formal methods Security services Intrusion detection system Hardware security Network security Information security Application security Human -- computer interaction Interaction design Social computing Ubiquitous computing Visualization Accessibility Concurrency Concurrent computing Parallel computing Distributed computing Multithreading Multiprocessing Artificial intelligence Natural language processing Knowledge representation and reasoning Computer vision Automated planning and scheduling Search methodology Control method Philosophy of artificial intelligence Distributed artificial intelligence Machine learning Supervised learning Unsupervised learning Reinforcement learning Multi-task learning Cross-validation Graphics Animation Rendering Image manipulation Graphics processing unit Mixed reality Virtual reality Image compression Solid modeling Applied computing E-commerce Enterprise software Computational mathematics Computational physics Computational chemistry Computational biology Computational social science Computational engineering Computational healthcare Digital art Electronic publishing Cyberwarfare Electronic voting Video games Word processing Operations research Educational technology Document management Book Portal WikiProject Commons GND : 4023422 - 8 Retrieved from `` https://en.wikipedia.org/w/index.php?title=Computer_hardware&oldid=865549840 '' Categories : Computer hardware Digital electronics Hidden categories : Use dmy dates from March 2017 Articles to be expanded from October 2018 All articles to be expanded Articles using small message boxes Wikipedia articles in need of updating from September 2018 All Wikipedia articles in need of updating Wikipedia articles with GND identifiers Talk Contents About Wikipedia Wikibooks Wikiversity Afrikaans Alemannisch Aragonés Asturianu বাংলা Беларуская Български Bosanski Brezhoneg Català Čeština Cymraeg Dansk Deutsch Eesti Ελληνικά Español Esperanto Euskara فارسی Føroyskt Français Gaeilge Gàidhlig Galego ગુજરાતી 한국어 हिन्दी Hrvatski Ilokano Bahasa Indonesia Interlingua IsiXhosa Íslenska Italiano עברית Basa Jawa Kaszëbsczi Қазақша Kurdî ລາວ Latina Latviešu Lëtzebuergesch Lietuvių Ligure Lingála Magyar Македонски Malagasy മലയാളം Bahasa Melayu Mirandés Монгол မြန်မာဘာသာ Nederlands नेपाली नेपाल भाषा 日本 語 Norsk Norsk nynorsk Олык марий ଓଡ଼ିଆ ਪੰਜਾਬੀ پښتو Plattdüütsch Polski Português Română Runa Simi Русиньскый Русский Scots Shqip සිංහල Simple English Slovenčina Slovenščina Soomaaliga کوردی Српски / srpski Srpskohrvatski / српскохрватски Suomi Svenska Tagalog தமிழ் తెలుగు ไทย Тоҷикӣ Türkçe Українська اردو Vèneto Tiếng Việt Winaray ייִדיש 粵語 中文 90 more Edit links This page was last edited on 24 October 2018, at 16 : 23 ( UTC ). Text is available under the Creative Commons Attribution - ShareAlike License ; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia ® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization. About Wikipedia

Question: what are the basic component of the computer
Answer: central processing unit