1. Definition;The use computer hardware and software to store,retrieve and manipulate.
2. Disadvantages
2.1. Violation of Privacy
2.2. Public Safety
2.3. Impact on Labour Force
2.4. Health Risk
2.5. Impact on Environment
3. Applications of IT
3.1. Education
3.2. Finance
3.3. Government
3.4. Health care
3.5. Science
3.6. Publishing
3.7. Travel
3.8. Manufacturing
4. Advantages
4.1. Speed
4.2. Reliability
4.3. Consistency
4.4. Communication
4.5. Storage
5. Categories of Computer
5.1. Supercomputer
5.2. Mainframe
5.3. Personal Computer (PC)
5.4. Mobile Computer and Devices
5.5. Embedded Computers
6. Differences
6.1. Physical Size
6.1.1. Size of supercomputer occupy a full room of equipment
6.1.2. Size of mainframe occupy a partial room to a full room of equipment
6.1.3. Size of personal computer fits on a desk
6.1.4. Size of mobile computer and devices either fit on your lap or in your hand.
6.1.5. Size of embedded computer is miniature,mounted on a circuit board.
6.2. Speed
6.2.1. Supercomputer; Tens of thousands of processors
6.2.2. Mainframe; Dozens of processors
6.2.3. Personal Computer; Single processor (1.5-2.5)
6.2.4. Mobile Computers and Devices; -----
6.2.5. Embedded Computers; -----
6.3. Storage
6.3.1. Supercomputer; Extremely large storage (eg. 3.1 PB)
6.3.2. Mainframe; Very large & addable storage (eg. 4.6 TB)
6.3.3. Personal computer; Large (eg. 500 GB)
6.3.4. Mobile Computers and Devices; -----
6.3.5. Embedded Computers