1. Input Device
1.1. Keyboard
1.1.1. Ergonomic keyboards
1.2. Mouse
1.2.1. Mechanical mouse
1.2.2. Optical mouse
1.2.3. Cordless mouse
1.3. Trackball
1.3.1. Joystick
1.3.2. Touchpad
1.3.2.1. Digitizer
1.3.2.1.1. Touch screen
1.3.2.1.2. Pen-based computing
1.3.3. Pointing stick
1.3.4. Graphics tablet
1.4. Scanner
1.4.1. Flatbed scanner
1.4.2. Bar Codes Readers
1.4.2.1. Hand held scaner
1.4.2.2. Cash Register scaner
1.4.2.3. Terminal
1.4.2.3.1. Dumb terminal
1.4.2.3.2. Smart terminal
1.4.2.3.3. Intelligent terminal
1.4.2.4. Optical Mark Readers
1.4.2.5. Optical Character Recognition
1.4.2.6. Magnetic Ink Character Recognition
1.4.2.7. Smart Cards Reader
1.4.3. Sheetfed scanner
1.4.4. Laser scaner
2. Output Device
2.1. Screen (monitor)
2.1.1. Text
2.1.2. Number
2.1.3. Image
2.1.4. Sound
2.1.5. VDO
2.1.6. Cathode ray tube
2.1.6.1. Scan rate
2.1.6.2. Resolution
2.1.6.3. Dot pitch
2.1.6.4. RAM-Card memory
2.1.7. Monitor Size
2.1.7.1. Flat-panel screens
2.1.7.2. Smart displays
2.2. Printer
2.2.1. Impact printer
2.2.1.1. Dot-matrix printer
2.2.1.1.1. Resolution
2.2.1.1.2. Speed
2.2.2. None-impact printer
2.2.2.1. Ink-jet printer
2.2.2.2. Laser printer