Hardware explain

      Computer hardware is a comprehensive term for all physical parts of a computr, as distinguished from the data it contains or operates on, and the software that provides instructions for the hardware to accomplish tasks. The boundary between hardware and software might be slightly blurry, with the existence of firmware that is software “built into” the hardware.

An exploded view of a modern personal computer and peripherals : -

(1) Scanner; 

(2) CPU (Microprocessor); 

(3) Memory (RAM); 

(4) Expansion cards (graphics cards, etc.); 

(5) Power supply; 

(6) Optical disc drive; 

(7) Storage (Hard disk or SSD); 

(8) Motherboard; 

(9) Speakers; 

(10) Monitor; 

(11) System software; 

(12) Application software; 

(13) Keyboard; 

(14) Mouse; 

(15) External hard disk; 

(16) Printer

          A typical D.C. consists of a computer case that holds the power supply, motherboard, hard disk drive, and often an optical disc drive. External devices such as a computer monitor or visual display unit, and a keyboard, pointing device are usually found in a pc

  

         The motherboard connects all processor, memory and peripheral devices together. The RAM, graphics card and processor are in most cases mounted directly onto the motherboard.. The central processing unit (microprocessor chip) plugs into a CPU socket, while the memory modules plug into corresponding memory sockets. Some motherboards have the video display adapter, sound and other peripherals integrated onto the motherboard, while others use expansion slots for graphics cards, network cards, or other I/O devices. The graphics card or sound card may employ a break out box to keep the analog parts away from the electromagnetic radiation inside the computer case. Disk drives, which provide mass storage, are connected to the motherboard with one cable, and to the power supply through another cable./ Usually, disk drives are mounted in the same case as the motherboard; expansion chassis are also made for additional disk storage. For extended amounts of data, a tape drive can be used or extra hard disks can be put together in an external case.

         The mouse and the keyboard are external devices plugged into the computer through connectors on an I/O panel on the back of the computer case. The monitor is also connected to the I/O panel, either through an onboard port on the motherboard, or a port on the graphics card.

     Capabilities of the pc hardware can sometimes extended by the addition of expansion cards connected via an expansion bus. Standard peripheral buses often used for adding expansion cards in personal computers include PCI, PCI Express (PCIe), and AGP (a high-speed PCI bus dedicated to graphics adapters, found in older computers). Most modern pc have multiple physical PCI Express expansion slots, with some of the having PCI slots as well.

Power Supply Unit :-

      This is a Power Supply Unit, or PSU, for an ATA computer. The top cover has been removed to show the internals. As can be seen from the stamped input rating (2A at 115V or 1A at 230V is 230 W), this is a low-power supply. Assuming 75% efficiency, that's about 160W maximum output.

Computer power supply unit with top cover removed. The power supply unit (PSU) converts general-purpose mains AC electricity to direct current (DC) for the other components of the computer.

       The rated output capacity of a PSU should usually be about 40% greater than the calculated system power consumption needs obtained by adding up all the system components. This protects against overloading the supply, and guards against performance degradation.

Processor :-

       The central processing unit, or CPU, is a part of a computer that executes instructions of a software program/. In newer PCs, the CPU contains over a million transistors in one integrated circuit chip called the microprocessor. In most cases, the microprocessor plugs directly into the motherboard. The chip generates so much heat that the PC builder is required to attach a special cooling device to its surface; thus, modern CPUs are equipped with a fanattached via heat sink.

         IBM PC compatible computers use an x86-compatible microprocessor, manufactured by Intel, AMD, VIA Technologies or Transmeta. Apple Macintosh computers were initially built with the Motorola 680×0 family of processors, then switched to the PowerPC series; in 2006, they switched to x86-compatible processors made by Intel..

Computer Case :-

  

      A computer case is an enclosure that contains the main components of a computer.. They are usually constructed from steel or aluminum combined with plastic, although other materials such as wood have been used. Cases are available in different sizes and shapes; the size and shape of a computer case is usually determined by the configuration of the motherboard that it is designed to accommodate, since this is the largest and most central component of most computers.

      The most popular style for DC is ATX,. although microATX and similar layouts became 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.

Motherboard :-

         The motherboard, also referred to as system board or main board, is the primary circuit board within a personal computer, and other major system components plug directly into it or via a cable. A motherboard contains a microprocessor, the CPU supporting circuitry (mostly integrated circuits) that provide the interface between memory and input/output peripheral circuits, main memory, and facilities for initial setup of the computer immediately after power-on (often called boot firmware or, in IBM PC compatible computers, a BIOS or UEFI).

        In many portable and embedded personal computers, the motherboard houses nearly all of the PC’s core components. Often a motherboard will also contain one or more peripheral buses and physical connectors for expansion purposes. Sometimes a secondary daughter board is connected to the motherboard to provide further expandability or to satisfy space constraints.

Main Memory :-

        A PC’s main memory is a fast primary storage device that is directly accessible by the CPU, and is used to store the currently executing program and immediately needed data. PCs use semiconductor random access memory (RAM) of various kinds such as DRAM, SDRAM or SRAM as their primary storage. Which exact kind is used depends on cost/performance issues at any particular time.

        Main memory is much faster than mass storage devices like hard disk drives or optical discs, but is usually volatile, meaning that it does not retain its contents (instructions or data) in the absence of power, and is much more expensive for a given capacity than is most mass storage. As a result, main memory is generally not suitable for long-term or archival data storage.

Hard Disk :-

        Mass storage devices store programs and data even when the power is off; they do require power to perform read and write functions during usage. Although flash memory has dropped in cost, the prevailing form of mass storage in personal computers is still the hard disk drive.

      If the mass storage controller provides additional ports for expandability, a PC may also be upgraded by the addition of extra hard disk or optical disc drives. For example, BD-ROMs, DVD-RWs, and various optical disc recorders may all be added by the user to certain PCs. Standard internal storage device connection interfaces are PATA, Serial ATA and SCSI. Solid state drives (SSDs) are a much faster (but also a much more expensive) replacement for traditional mechanical hard disk drives.

Visual Display Unit :-

       A visual display unit, computer monitor or just display, is a piece of electrical equipment, usually separate from the computer case,. which displays visual images without producing a permanent computer record. A display device is usually either a CRT or some form of flat panel such as a TFT LCD.. Multi-monitor setups are also quite common.

     The display unit houses an electronic circuitry that generates its picture from signals received from the computer. Within the computer, either integral to the motherboard or plugged into it as an expansion card, there is pre-processing. circuitry to convert the microprocessor’s output data to a format compatible with the display unit’s circuitry. The images from computer monitors originally contained only text, but as graphical user interfaces emerged and became common, they began to display more images and multimedia content.

     The term “monitor” is also used,, particularly by technicians in broadcasting television, where a picture of the broadcast data is displayed to a highly standardized reference monitor for confidence checking purposes.

Video Card :-

       The video card otherwise called a graphics card,. graphics adapter or video adapter—processes the graphics output from the motherboard and transmits it to the display. It is an essential part of modern multimedia-enriched computing.. On older models, and today on budget models, graphics circuitry may be integrated with the motherboard, but for modern and flexible machines, they are connected by the PCI, AGP, or PCI Express interface.

      When the IBM PC was introduced, most existing business-oriented personal computers used text-only display adapters and had no graphics capability.. Home computers at that time had graphics compatible with television signals, but with low resolution by modern standards owing to the limited memory available to the eight-bit processors available at the time.

Keyboard :-

      A “Model M” IBM computer keyboard from the early 1980s.. Commonly called the “Clicky Keyboard” due to its buckling spring key spring design,, which gives the keyboard its iconic ‘Click’ sound with each keystroke.

       A keyboard is an arrangement of buttons that each correspond to a function, letter, or number. They are the primary devices used for inputting text. In most cases, they contain an array of keys specifically organized with the corresponding letters, numbers, and functions printed or engraved on the button. They are generally designed around an operators language, and many different versions for different languages exist.

      In English, the most common layout is the QWERTY layout, which was originally used in typewriters. They have evolved over time, and have been modified for use in computers with the addition of function keys, number keys, arrow keys, and keys specific to an operating system. Often, specific functions can be achieved by pressing multiple keys att once or in succession, such as inputting characters with accents or opening a task manager. Programs use keyboard shortcuts very differently and all use different keyboard shortcuts for different program specific operations, such as refreshing a web page in a web browser or selecting all text in a word processor.

Mouse :-

      A computer mouse is a small handheld device that users hold and slide across a flat surface, pointing at various elements of a graphical user interface with an on-screen cursor,, and selecting and moving objects using the mouse buttons. Almost all modern personal computers include a mouse; it may be plugged into a computer’s rear mouse socket, or as a USB device, or, more recently, may be connected wirelessly via an USB dongle or Bluetooth link..

       In the past,, mice had a single button that users could press down on the device to “click” on whatever the pointer on the screen was hovering over. Modern mice have two, three or more buttons, providing a “right click” function button on the mouse, which performs a secondary action on a selected object, and a scroll wheel, which users can rotate using their fingers to “scroll” up or down. The scroll wheel can also be pressed down, and therefore be used as a third button. Some mouse wheels may be tilted from side to side to allow sideways scrolling. Different programs make use of these functions differently,, and may scroll horizontally by default with the scroll wheel, open different menus with different buttons, etc. These functions may be also user-defined through software utilities..

       Mice traditionally detected movement and communicated with the computer with an internal “mouse  ball”,, and used optical encoders to detect rotation of the ball and tell the computer where the mouse has moved.. However, these systems were subject to low durability, accuracy and required internal cleaning. Modern mice use optical technology to directly trace movement of the surface under the mouse and are much more accurate,, durable and almost maintenance free. They work on a wider variety of surfaces and can even operate on walls, ceilings or other non-horizontal surfaces.