What is a Computer? Types of Computer
What is Computer?
Definition of Computer: Computer is an electronic device or machine i.e. a system that has the ability to accept data, internally store and automatically execute a program of instructions, performs mathematical, logical and manipulative operations on data and reports the result.
Functions of Computer
Computers has 4 important functions.
- The computer receives the programs created by the user and stores them in the memory and executes the program according to the user’s instructions.
- Computer receives data through keyboard, mouse, disk etc.
- After receiving the data, the computer processes the data.
- When the data processing is done, it gives the result through monitor, printer, plotter etc.
Characteristics of Computer
- High speed.
- Logical decision.
- Endless life.
Types of Computer
The computer systems are available in various sizes and with a variety of peripherals or support devices to cover just about every processing need because The variety of computer power or functions available computers are classified on the basis of
Based on purpose computers are categorized into two
- General purpose computer.
- Special purpose computer
What is a General purpose computer?
General-purpose computers are used to handle many tasks. This is possible by the stored program concept. Usually general computers are slower than special purpose computers when applied to the same tasks.
What is a Special purpose computer?
Special purpose computers are used to control the collection of tools on certain highways and in automobiles, weapons and games etc.
Computers are of three categories based on types
- Analog computer.
- Digital computer.
- Hybrid computer.
What is an Analog computer?
The word Analog comes from Analogy. Which means similarity. Analog computers work through analog signals.
Characteristics of analog computers
- Analog signals rise and fall in phases.
- Analog computer output is usually provided by a plotter.
- An analog computer designed for one type of task. Therefore, different types of analog computers are developed for different tasks.
Use of analog computers
Analog computer is used for motor vehicle speedometer, pied rule, operational amplifier etc.
What is a Digital computer?
The word Digital is derived from the word Digit. Digital computer works on the basis of number processing. Digital computers do all kinds of work with the symbols binary i.e. 0 (zero) and 1 (one).
Characteristics of Digital computers
- The result is displayed directly on the monitor or any other output device.
- The same computer can be used for different purposes.
- Accuracy of work is hundred percent (100%).
Use of Digital computers
Most of the computers we use are usually digital computers.
What is a Hybrid Computer?
Hybrid computers are made by combining analog and digital computers.
Characteristics of hybrid computers
Input is analog nature, but output is digital nature.
Use of hybrid computers
- Hybrid computers are used in hospitals to monitor patient’s blood pressure, heart rate, body temperature etc.
- Hybrid computers are used in nuclear power plants.
- Hybrid computers are used in fighter jets, space shuttles and missile launches.
Based on capacity computers are classified into four:
- Micro computer.
- Mini computer.
- Mainframe computer.
- Super computer.
What is a Micro computer?
Micro computers are microprocessor based small desktop systems with varying capability depending the on input/output and secondary storage device supporting it. The brain of a microcomputer is the microprocessor that is an integrated circuit consisting of thousands of transistors squeezed into a tiny chip of silicon.
What is a Mini computer?
A mini computer system performs the basic arithmetic and logic functions and supports some of the programming language used with larger computer systems. They are physically smaller and have a small storage capacity than mainframes.
What is a Mainframe computer?
Larger computers generally consist of modules mounted on a chassis are known as mainframe computers. They vary in size from those slightly large than a mini computer to super computers. Some of the mainframe computers are greater processing speed, greater storage capacity, a larger variety of input/output devices, support for a number of high-speed secondary storage device multi programming and time sharing. Large business, universities, government agencies, and the military generally use mainframe computer system.
What is a Super computer?
The large and powerful mainframe computer is called a super computer. The astronomical cost of super computer has limited their development to only few hundred worldwide. Super computers are applied to the solution of very complex and sophisticated scientific problems and for natural security purposes of advanced nations.
Computers for individual users
There are six types of computers, which are used for individual users. These computers are also the examples of personal computers or PCs that are designed for use by a single person. Personal computers are also called microcomputers.
However, the six types of computer in these categories are as follows:
What is Desktop computer?
Desktop computer is the most common type of personal computers, which is designed to sit on a desk or a table. These types of computers are used at homes, schools, and offices.
What is a Workstation?
Workstation is a specialized single user computer, which has more power and features than standard desktop computers. The scientists, engineers and animators who need a system with high speed and power to perform sophisticated works.
What is Notebook/laptop computers?
Notebook/laptop computers can operate on alternating current or special batteries. It generally weights less than 8 pound and some of less than 3 pounds.
Benefits of Laptop
- Much smaller and more power efficient than desktop PCs.
- A UPS is used to run a desktop in load shedding. Which has a backup time of 15-30 minutes. But the battery is connected to the laptop. If there is no electricity, it can run for 2-8 hours depending on the model.
- It is easily portable. Much smaller and lighter than desktop in size. The laptop looks like a small briefcase.
- It uses a touchpad instead of a mouse.
Disadvantages of laptops
- Desktop PCs stay in one place. Don’t move too much. Due to which it is less likely to fall out of hand or break due to other reasons. But laptops are portable, so they can fall out of hand and break.
- A typical laptop has less capacity than a desktop. Again, the price of laptops with the same capacity as desktops has skyrocketed. So if you compare in terms of price, the price of desktop PC is much less compared to laptop.
- If any part of the desktop is damaged, it can be easily replaced. But as laptop spare parts are difficult to find, their prices are also relatively high.
What is a Tablet computer?
It offers all the functionalities of a notebook PC but they are lighter and can accept input from a special pen called a stylus or a digital pen that is used to type or write directly on the screen.
What is a Handheld computers?
Handheld computers are computing devices small enough to fit in hand. A popular type of handheld computer is the personal digital assistant. It is no larger than a small appointment book. It is normally used for special applications such as taking notes, collecting telephone numbers and addresses and keeping track of dates or agendas.
What is a Smart computer?
Some cellular phones offer advanced features not generally found in cellular phones, they are sometimes called smart computer. These features can include web and e-mail access, special software such as personal organizers or special hardware i.e. digital cameras or music players etc.