Basic components of computer

• Enclosure or Case

• Encases all the components of a computer.
• Square or rectangular in shape.
• Made of steel, Aluminium or plastic.  

   ⦁ Power supply

• Provides power to the components of the computer.
• Rated in Watts (A unit of power). Mostly 250 to the 400-watt range.
• Converts 110 Volt or 220 Volt  AC current to the DC voltages required to operate.
• The required voltages may be +3.3 VDC, + 5 VDC, -5VDC  (ground), +12 VDC, -12 VDC (ground) and +5 VDC  standby.

      Note:  +3.3 VDC & +5 VDC standby voltages are used only by ATX motherboards, not          AT motherboards.

   ⦁ Motherboard

• The backbone of the computer, also known as the system board or Planar board.
• Olive green or brown circuit board that lines the bottom of the computer
• CPU (Central processing unit), expansion slots, underlying circuitry, video components, RAM (Random Access Memory) slots etc are placed on the system board or Motherboard. 
• Read more about Motherboard Form Factors

   ⦁ CPU / Processor

• Control & direct all the activities of the computer.
• The processor is a chip consisting of an array of millions of transistors.
• Generally located away from expansion slots.
• Accompanied by heat sink & a fan to cool itself.

      More on Chipsets

   ⦁ Memory

• A physical device that stores information permanently or temporarily.
• .Types: Volatile & Non-volatile
• Volatile memory stores information only when the device is powered ON. RAM is a volatile memory.
• Non-Volatile memory stores information permanently even after the power cycle. ROM, Hard disks, CMOS,  optical disks etc are Non-volatile memories.

        Want to know about different types of memory?  

   ⦁ Storage devices

• A computer hardware used to store & retrieve data such as files & applications.
• Stores large volume of files permanently.
• Hard disks, External hard disks, USB storage devices,  DVD ROM drives, Tape backup devices, Optical drives etc are secondary storage devices or Non-volatile memories.

         RAID types

    ⦁ Adapter cards

• Also known as an expansion card.
• It is an additional circuit board added by the user to increase the capabilities of the computer.
• Expansion cards can only be installed in the same bus type of expansion slot is provided in the motherboard.

• Most common expansion cards  

1. Video card      
2.  Network Interface Card (NIC) 
3.  Soundcard 

   ⦁ Ports & cables

A port is a connector on a computer into which a cable can be plugged.

• Peripheral port connector types

     a. DB - series   

        b. RJ - series      

        c. Universal serial Bus (USB)     

        d. PS/2 (Mini DIN)      

        e. RCA        f. Infrared       

        g. HDMI       

        h. Centronics      

        i. IEEE1394 (Firewire)

• Common Interfaces & Cables

     a. Parallel    
      b. Serial     
      c. USB      
      d. RCA       
      e. PS/2      
      f. Infrared      
      g. IEE 1394 (fire wire)

   ⦁ Display devices

      Display systems convert computer signals into text and pictures and display them on a           screen.

• How Display systems work?

        A computer sends a signal to video adapter to display a  particular graphic or character.  Then the video adapter converts the single instruction into several instructions that tell the display device how to draw the required graphic & sends the instructions to the display device.       

•  Types of video adapters

     a. Monochrome 
        b. EGA     
        c. CGA    
        d. VGA 
        e. Super-VGA
        f. HDMI      
        g. DVI      
        h. Display port adapter

•  Types of display

       a. CRT   
        b. LCD   
        c. LED