1. Project on computers Made by : maneet kaur Taneja 9-d Roll number:24
School: mother Mary's school

2. Computer science
Computers

3. Parts of a computer
The basic parts of a desktop computer are computer case, monitor, keyboard, mouse and power cord. Each plays an important role whenever a computer is used. computer consists of hardware and software. Hardware is the external body of a computer such as Central processing unit(cup), monitor, keyboard and mouse whereas software is internal body of a computer such as links and applications.

4. Computer case
A computer case is the metal and plastic box which contains main components of a computer including the motherboard, central processing unit and power supply. The front of the case has an off/on button and one or more optical drives. Computer cases comes in different sizes and shapes. A desktop face lies flat on the desk, and the monitor usually sits on the top of it. A tower case is tall and sits next to the monitor on floor. All-in-computers come with internal components built into monitor which eliminates the need for separate case.

5. Monitor
A computer monitor is an electronic device that shows pictures for computers. Monitors often look similar to television. The main difference between a monitor and a television is that a monitor does not have a television tuner to change channels. Monitors also have higher display resolution than televisions. A high display resolution makes it easier to see small letters and fine graphics. The CRT monitor are big and heavy and use a lot of desk space and electricity. It is the oldest technology used by monitors and is based on the cathode ray tube technology that was developed for televisions. Monitors ate made with better parts which give a higher display resolution and picture sharpness than a television. This type of monitor is no longer popular.

6. Keyboard
In computing, a computer keyboard is a typewriter-style device which uses an arrangement of buttons or keys to act as a mechanical lever or electric switch. Following the decline of punch cards and paper tape, interaction via teleprompter-style keyboards became the main input device for computers. A keyboard typically has characters engraved or printed on the key(buttons) and each press of a key typically corresponds to a single written symbol. However, to produce some symbols requires pressing and holding several keys simultaneously or in sequence. While most keyboard keys produce actions or execute commands. ,

7. Mouse
A computer mouse is a pointing device(hand control) that deflects two-dimensional motion relative to a surface. This motion is typically translated into motion of a pointer on a display which allows a smooth control of the graphical user interface. Physically, a mouse consists of an object held in one’s hand, with one or more buttons. Mice often also feature other elements, such as touch surfaces and wheels, which enable additional control and dimensional input. Mickey's per second is a unit of measurement for the speed and development of a computer mouse where direction is often expressed as “horizontal” versus "vertical” Mickey count. However, the speed can also refer to the ratio between how many pixels the cursor moves. Nearly all mice have an integrated input primarily intended for scrolling on top, usually a single-axis digital wheel or rocket switch which can also be depressed to act as a third button. Though less common, many mice instead have two-axis inputs such as tilt able wheel, trackball or touchpad ,

8. Central processing unit
A central processing unit (CPU) is the electronic circuitry within a computer that carries out the instruction of a computer program by performing the basic arithmetic, logical, control and input/output (I/O) operations specified by the instructions. The computer industry has used the term "central processing unit" at least since the early 1960s.[1] Traditionally, the term "CPU" refers to a processor, more specifically to its processing unit and control unit (CU), distinguishing these core elements of a computer from external components such as main memory and I/O circuitry.[2]
The form, design and implementation of CPUs have changed over the course of their history, but their fundamental operation remains almost unchanged. Principal components of a CPU include the arithmetic logic unit (ALU) that performs arithmetic and logic operations, processor registers that supply operands to the ALU and store the results of ALU operations, and a control unit that orchestrates the fetching (from memory) and execution of instructions by directing the coordinated operations of the ALU, registers and other components.

9. Power supply unit (computer)
A power supply unit (or PSU) converts mains AC to low-voltage regulated DC power for the internal components of a computer. Modern personal computers universally use switched- mode power supplies. Some power supplies have a manual switch for selecting input voltage, while others automatically adapt to the mains voltage.
Most modern desktop personal computer power supplies conform to the ATX specification, which includes form factor and voltage tolerances. While an ATX power supply is connected to the mains supply, it always provides a 5 Volt standby (5VSB) voltage so that the standby functions on the computer and certain peripherals are powered. ATX power supplies are turned on and off by a signal from the motherboard. They also provide a signal to the motherboard to indicate when the DC voltages are in spec, so that the computer is able to safely power up and boot. The most recent ATX PSU standard is version 2.31 of mid-2008.