HARDWARE

• A personal computer is made up of multiple physical components of computer hardware, upon which can be installed an operating system and a multitude ofsoftware applications to perform the operator's desired functions.
• Though a PC comes in many different forms, a typical personal computerconsists of a case or chassis in a tower shape (desktop), containing components such as a motherboard.
• MOTHER BOARD
• The motherboard is the main component inside the case. It is a large rectangular board with integrated circuitry that connects the rest of the 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 the motherboard include:
• The central processing unit (CPU) 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 heat sink and fan.
• The chip set mediates communication between the CPU and the other components of the system, including main memory.
• RAM (Random Access Memory) stores all running processes (applications) and the current running OS.
• The BIOS includes boot firmware and power management. The Basic Input Output System tasks are handled by operating system drivers.
• 
  
  
  
  Internal Buses connect the CPU to various internal components and to expansion cards for graphics and sound.
• Current
• The north bridge memory controller, for RAM and PCI Express
• PCI Express, for expansion cards such as graphics and physics processors, and high-end network interfaces
• PCI, for other expansion cards
• SATA, for disk drives
• Obsolete
• ATA (superseded by SATA)
• AGP (superseded by PCI Express)
• VLB VESA Local Bus (superseded by AGP)
• ISA (expansion card slot format obsolete in PCs, but still used in industrial computers)

            

             POWET SUPPLY

A power supply unit (PSU) converts alternating current (AC) electric power to low-voltage DC power for the internal components of the computer. Some power supplies have a switch to change between 230 V and 115 V. Other models have automatic sensors that switch input voltage automatically, or are able to accept any voltage between those limits. Power supply units used in computers are nearly always switch mode power supplies (SMPS). The SMPS provides regulated direct current power at the several voltages required by the motherboard and accessories such as disk drives and cooling fans.

SOUND CARD

Enables the computer to output sound to audio devices, as well as accept input from a microphone. Most modern computers have sound cards built-in to the motherboard, though it is common for a user to install a separate sound card as an upgrade. Most sound cards, either built-in or added, have surround sound capabilities.

OPERATING SYSTEM

An operating system (OS) is software (programs and data) that runs on computers and manages the computer hardware and provides common services for efficient execution of various application software.

For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between application programs and the computer hardware,^[1][2] although the application code is usually executed directly by the hardware, but will frequently call the OS or be interupted by it. Operating systems are found on almost any device that contains a computer—from cellular phones and video game consoles to supercomputers and web servers. Operating systems are two-sided platforms, bringing consumers (the first side) and program developers (the second side) together in a single market. Some popular modern operating systems for personal computers include Microsoft Windows, Mac OS X, andGNU/Linux.

"Operating Systems" is also a field of study within computer science. An operating system is the medium of interaction(communication) between application program and computer hardware.