1. Computer Case Houses computer components Provides physical, environmental and electrostatic protection Source for the following: wikipedia.org-Personal_computer_hardwarewikipedia.org-Personal_computer_hardware

2. Monitor Allows the computer to communicate with the operator real time and interactively.

3. Monitor The performance of a monitor is measured by the following parameters:  Luminance is measured in candelas per square meter.  Viewable image size is measured diagonally. For CRTs, the viewable size is typically one inch smaller than the tube itself.  Aspect ratio is the ratio of the horizontal length to the vertical length. 4:3 is the standard aspect ratio. That would make a screen with a width of 1024 pixels have a height of 768 pixels. If a widescreen display has an aspect ratio of 16:9, a display that is 1024 pixels wide will have a height of 576 pixels.  Display resolution is the number of distinct pixels in each dimension that can be displayed. (It does not mean currently displayed.) Maximum resolution is limited by dot pitch.  Dot pitch is the distance between pixels of the same color in millimeters. In general, the smaller the dot pitch, the sharper the picture will appear.

4. Monitor The performance of a monitor is measured by the following parameters (continued) :  Refresh rate is the number of times in a second that a display is illuminated. Maximum refresh rate is limited by response time.  Response time is the time a pixel in a monitor takes to go from active (black) to inactive (white) and back to active (black) again, measured in milliseconds. Lower numbers mean faster transitions and therefore fewer visible image artifacts.  Contrast ratio is the ratio of the luminosity of the brightest color (white) to that of the darkest color (black) that the monitor is capable of producing.  Power consumption is measured in watts.  Viewing angle is the maximum angle at which images on the monitor can be viewed, without excessive degradation to the images. It is measured in degrees horizontally and vertically.

5. Motherboard (2) 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.

6. Motherboard Components directly attached to the motherboard include: (3) The central processing unit (CPU) which performs most of the calculations that enable a computer to function, and is sometimes referred to as the "brain" of the computer. The chip set (associated with the CPU) mediates communication between the CPU, RAM and the other components of the system. (4) RAM Stands for Random Access Memory and stores all running processes (applications) and the Operating System.

7. Motherboard BIOS programs are stored on a chip and are built to work with various devices that make up the complementary chipset of the system. BIOS is boot firmware, designed to be the first code run by a PC when powered on. The initial function of BIOS is to identify, test, and initialize system devices like the video display card, hard disk, floppy disk and other hardware. BIOS has a small library of basic input/output functions that are used to operate and control peripherals such as the keyboard, text display functions and so forth.

8. Motherboard (5) An expansion card (also adapter card or IO card) is a printed circuit board that can be plugged into an expansion slot on the motherboard to add more functionality to a computer system. One edge of the expansion card has contacts that fit into a slot to establish the electrical connection between the card's electronics and the motherboard via the Internal Bus. Video, Network, Sound and MODEM cards are examples of expansion cards.

9. Power Supply (6) Provides all power required to run the logic circuits, cooling fan(s),Hard Drive(s) and CD/DVD Drive(s).

10. CD/DVD Drive (7) Compact Discs and Digital Video Disc are common types of optical removable media devices which can be read from and recorded to.

11. Hard Disk Drive (8) HD or HDD is a non- volatile storage device that store digitally encoded data on rapidly rotating platters with magnetic surfaces.

12. Hard Disk drive Used to store and retrieve:  Operating System program instructions  Application program instructions  User data  Environmental and System data  Temporary computer required stored data HD common ratings:  Capacity (40 GB, 500 GB, 1 TB)  Spin speed (5400 rpm, 7200 rpm)  Data transfer rate  Seek time

13. Keyboard and Mouse (9) Both are input devices, used to provide information requested by the Operating System or Application software.

18. USB Flash Drive Consists of flash memory data storage integrated with a USB (Universal Serial Bus) 1.1 or 2.0 interface. USB flash drives are typically removable and rewritable, and as replacements for floppy disks drives. They are smaller, faster, have thousands of times more capacity, and are more durable.