Categories of Computers

What is a Computer?

An electronic device (machine), that performs four basic operations: input, processing, output and storage.

or

Computer is an electronic device operating under the control of instructions stored in its own memory, that accepts data, process the data, produce results, and store the results for future use.

Categories of Computer

• Supercomputers
• Mainframes
• Personal Computers
• Mobile Computers and Devices
• Embedded Computer

 For more information on categories of computers, click here / here. 

Click here to directly go to the file of Chapter 1 - Introduction to Information Technology (IT) lecture notes.

1. Supercomputers

A supercomputer is the fastest, most powerful, most expensive computer and used for very complex, sophisticated job such as nuclear research, calculating weather patterns, petroleum exploration, online banking, automotive design.

Physical size

Full room of equipment

Speed

The fastest supercomputer are capable of processing billions of program instructions per second.

Can operate at speeds measured in picoseconds-1,000 times as fast as microcomputers.

Storage

Can store more than 20,000 times the data and information of an average desktop computer.

2. Mainframes

A mainframe is a large, expensive, powerful computer that can handle hundreds or thousands of connected users simultaneously (multi-user) and storing tremendous amounts of data, instructions and information. Mainframes are often used in businesses that manage large amounts of data, for example, insurance companies use mainframes to process information about millions of policyholders.

For more information on mainframes, click this link.

Physical size

 Partial room to a full room of equipment.

Speed
Powerful computer that handle hundreds or thousands of connected users simultaneously at the same time.

Storage
Can store tremendous amounts of data, instructions, and information; enterprises are able to bill millions of customers, prepare payroll for thousands of employees, and manage thousands of item in inventory.

Advantages

Huge memory/Large - Able to store tremendous amounts of data, instructions & information.
High speed/Powerful - they can process vast amounts of data, very quickly.
Super reliable - incredibly reliable with mean time between failure (MTBF) up to 20 years because lot of circuitry is designed to detect and correct errors.
Multi User - They allow several users (sometimes hundreds) to use the computer at the same time.

3. Personal Computers

Personal computer is a computer that can perform all its input, processing, output and storage activities by itself. Two types of personal computers are desktop computers, and notebook computers.

Physical size

Fits on a desk

Speed

Various depends on the memory and processors

Storage

Various depends on the hard drive size

4. Mobile Computers & Devices

Mobile Computer is a personal computer (that can perform all of its input, processing, output, and storage activities by itself) that you can carry from place to place.

Examples: notebook computers, netbook, Table PCs

Mobile Device is a computing device small enough to hold in your hand.

Examples: Smart phones and PDAs, E-book readers, Handheld computers, Portable media players, and Digital cameras.

Laptop/Notebook

Portable, often designed to fit on your lap. Thin and lightweight, powerful as the average desktop computer.

Netbook

Smaller, lighter than a notebook computer. Not as powerful as a notebook computer

Tablet PC

Special type of notebook computer that you can interact with by touching the screen by using finger or digital pen.

Smart phones and PDAs

 Smart phone is an Internet-enable phone. Provides personal information management functions such as calendar, an appointment book, address book, calculator and notepad

E-book reader

Is a handheld device that is used primarily for reading e-books. Have a touch screen and are Internet-enable.

Handheld computers

Small computer enough to fit in one hand. Many handheld computers are industrial-specific and serve the needs of mobile employees such as meter readers and parcel delivery people.

Portable Media Player

Is a mobile device on which you can store, organize and play digital media such as music, watch videos, movies and view photos.

Digital camera

Is a device that allows user to take pictures and store the photographed images digitally.

Physical size

Fits on the lap, palm, pocket 

Speed

 May slower than a personal computer.

Storage

Small storage media

5. Embedded Computer

Special-purpose computer that functions as a component in a larger product and perform various functions depending on the product.

For more information on embedded computers, click this link.

Consumer Electronics

 Mobile and digital telephones
Digital televisions
Cameras
Video recorders
DVD players and recorders
Answering machines

 Home Automation Devices

Thermostats

Sprinkling systems

Security monitoring systems

Appliances Lights 

Automobiles

Antilock brakes

Engine control modules

Airbag controller

Cruise control

Process Controllers and Robotics

 Remote monitoring systems
Power monitors
Machine controllers
Medical devices

Computer Devices and Office Machines
 Keyboards
Printers
Faxes
Copiers

Some of the embedded computers designed to improve the safety, security and performance in today’s automobiles

Physical size

Small

Speed

May be slower than a mobile computer and devices

Storage

Limited or small storage media