Computer Definition and History

Computer Full Form – 

• C= Commonly
• O= Operating
• M= Machine
• P= Particular
• U= Used
• T= Trade
• E= Education
• R= Research

Definition: A computer is a commonly operating machine that is used separately for trade, education, and research. It is called a computer.

Or: A computer is an electronic machine that receives information from input devices and, after performing various types of calculations on it, provides us with meaningful information through output devices. It is called a computer.

• Nowadays, computers are extensively used in government undertakings, colleges, universities, business, technical institutions, the medical field, education, industries/businesses, factories, and government policies.

Steps to turn on the computer:

1. Turn on the power button.
2. Turn on the UPS button.
3. Turn on the CPU button.
4. After this, we reach the desktop and see the following type of screen.

Steps to turn off the computer:

1. First, with the help of the mouse, we come to the taskbar.
2. Click on the Start button.
3. Click on the Shutdown option and then click OK.
4. Turn off the UPS button.
5. Turn off the power button.

Evolution and Generations of Computer:

• The modern computer is the integrated result of countless inventions, ideas, and developments made by numerous individuals over the past several thousand years.
• The first device used for calculation, the abacus, was invented in China.
• In the early 17th century, Scottish mathematician John Napier invented logarithms, and later, he created a calculating device called Napier’s Bones, which could easily multiply large and decimal numbers.
• In 1642, Blaise Pascal created the world’s first mechanical calculator, which could perform addition and subtraction of the decimal system. It was named Pascaline.
• Charles Babbage is called the Father of the Modern Computer because he created the Difference Engine in 1821 and the Analytical Engine in 1833, which can be called the ancestors of the modern computer.
• In 1887, Herman Hollerith created an electro-mechanical card-based tabulating machine, which was used by the US Census Bureau in 1890 to compile census-related data.

Generations of Computer Development: The development process of electronic computers has been divided into five generations, which are as follows:

First Generation of Computers:- 1942–1955

Characteristics:

1. Vacuum tubes (निर्वात ट्यूब) were used in this generation.
2. Machine language (मशीनी भाषा) was used, and it was very difficult for programming.
3. Punch cards were used for input.
4. ENIAC, UNIVAC, and IBM Mark-I are examples of this generation.
5. These computers were large in size and consumed more energy.
6. In 1952, writing programs became somewhat easier with the invention of Assembly Language by Dr. Grace Hopper.

Second Generation of Computers:- 1955–1964

Characteristics:

1. Transistors were used instead of vacuum tubes, which were lighter, smaller, and consumed less electricity.
2. Batch operating systems were introduced in these computers.
3. High-level languages like COBOL and FORTRAN were developed by IBM. This made programming easier. Examples: IBM-700 series, IBM-1400, 1600 series, Honeywell-400 to 800 series.

Third Generation of Computers:- 1964–1975

Characteristics:

1. The use of Integrated Circuits (IC) started instead of transistors.
2. Computers of this generation were lighter, less expensive, and faster. They were also more reliable.
3. High-level languages like PL/1, Pascal, and BASIC were developed. Examples: IBM-360, 370, VAX-750.

Fourth Generation of Computers:- 1975–1989

Characteristics:

1. Microprocessors were used instead of ICs.
2. Semiconductor memory replaced magnetic disks and tapes.
3. High-speed computer networks like LAN and WAN were developed. Examples: Pentium-1, 2, 3, 4 and computers from Apple, Compaq, Hewlett-Packard companies. The first microprocessor computer was Intel 8008.

Fifth Generation of Computers:- 1989 to present

Characteristics:

1. The development of the Internet, email, and the World Wide Web occurred in the field of networking.
2. Efforts are being made to incorporate artificial intelligence capabilities into new computers so that computers can make decisions on their own according to situations.
3. This generation is based on ULSI (Ultra Large Scale Integration).
4. Storage capacity increased with the use of magnetic bubble memory. Examples: PARAM 10,000, supercomputers manufactured by India, etc.

Classification of Computers:

1. Analog Computer: These computers do not work on digits; instead, they work directly on physically available data such as physical data like temperature, pressure, length, electricity or the flow of other substances, etc., which are in continuous physical form. Example: The analog computer installed at a petrol pump measures the quantity of petrol in liters and simultaneously calculates and displays the price on the screen. Analog signals are continuous.

2. Digital Computer: These computers work on digits. They operate on data that is in the form of binary digits. The signals of digital computers are discrete (not continuous). These computers are used for multi-purpose and various tasks.

3. Hybrid Computer: These computers have a combination of the qualities of both analog and digital computers. Therefore, these computers are widely used in the medical field, where they receive a patient’s temperature, heartbeat, blood pressure, etc., in the form of analog signals and then convert them into digital signals to display accurate data in the form of digits.

Classification Based on Size: Currently, computers are broadly divided into four parts based on their size:

1. Micro-computer: These are small in size and low in cost. These computers are used in our homes, offices, schools, etc. Only one person can work on these computers at a time. They are also called Personal Computers (PCs). PCs are of several types:

(a) Desktop Computer: These are kept on a table and work is done on them. They are the most prevalent currently.

(b) Laptop Computer: These are similar to briefcases. A person can work by keeping them on their lap. They can be easily carried from one place to another.

(c) Palmtop Computer: These are so small that they can even be held in the palm and used for work.

2. Mini computer: These are medium-sized (mid-range) general-purpose computers. They have more than one CPU. More than one person can work on them simultaneously. They are primarily used in large offices, banks, etc.

1. Mainframe Computer: These are very large in size, have extremely fast processing speeds, and are expensive. They are used in railway reservations, insurance companies, and large business organizations. Example: IBM-4300.

2. Supercomputer: These are the largest in size, have very fast processing capabilities, and cost billions of rupees. They are used in scientific research organizations, weather forecasting, controlling nuclear plants, space technology, engineering, etc. The development of supercomputers in India was done by C-DAC (Centre for Development of Advanced Computing) located in Pune.

Characteristics of Computer:

1. Speed (गति)
2. Accuracy (शुद्धता)
3. Diligency (सक्षमता)
4. Power of Remembering (स्मरण शक्ति)
5. Versatility (व्यापक उपयोगिता)
6. Automation (स्वचालन)
7. Storage (भंडारण)

Limitations of Computer:

1. Lack of thinking and understanding ability.
2. Lack of self-error correction capability.
3. It is impossible for computers to perform physical work on their own.

Knowledge of Keyboard: This is the input unit of the computer. Information is given to the computer through it. It is of two types: XT and AT.

Esc Button: By pressing this button, you can exit any option. That is, it performs the Exit function.

Function Keys: These are on the keyboard from F1 to F12. They are used for specific functions.

Numeric Keys: These are on the keyboard from 0 to 9.

Backspace Key: This deletes characters one by one from the right side. That is, it acts like an eraser.

CAPS LOCK: There is a light on the keyboard for this. When the light is on, we type in capital letters. And when the light is off, we type in small letters. (Toggle Key)

ALPHAMATIC KEYS: These are A to Z on the keyboard.

Shift Key: This key does not perform any function alone. And it performs many functions with other keys. For example, the symbols given above the numeric keys can be accessed by pressing and holding the Shift key.

Ctrl Key: The Control key also does not perform any function alone. It performs many functions with other keys. For example: Ctrl + A = Select All

Enter Key: By pressing this key, we can go to a new line.

Window Key: This key opens the Start menu commands button.

ALT KEY: This key does not perform any function alone on the keyboard. And it performs many functions with other keys. For example: Alt + F4 = Close Current Application

Space Key: By pressing this key, we give a gap between words. We give a gap of 0.5mm with it.

Right Key: By pressing this key, we can open the options of the right button of the mouse.

Print Screen SysRq: With the help of this key, we can create an image (screenshot) of any application.

Scroll Lock: There is a light on the keyboard for this button. When the light is on, we can use the third button of the mouse, and when the light is off, we cannot use it.

Pause Break Key: With this, we can stop a running movie or game at the same point.

Insert Key: By pressing this key, we can add new words in the middle of any line.

Home Key: By pressing this key, we can come to the beginning of the current line.

End Key: By pressing this key, we can go to the end of the current line.

Based on Application:

• Analog Computers:

  • Process continuous physical data (e.g., temperature, pressure, speed).
  • Represent data as continuous electrical signals.
  • Often used for specialized tasks like scientific and engineering applications, and real-time control systems.
  • Output is often displayed on dials or graphs.
  • Generally less precise than digital computers for complex calculations.

• Digital Computers:

  • Process discrete data, represented as binary digits (0s and 1s).
  • Perform arithmetic and logical operations on these digits.
  • Highly accurate and versatile.
  • Used for a wide range of applications, from personal computing to complex scientific simulations.
  • Can store and retrieve large amounts of information.

• Hybrid Computers:

  • Combine features of both analog and digital computers.
  • Can process both continuous and discrete data.
  • Often used in specialized applications where both types of processing are needed, such as medical diagnosis (measuring vital signs – analog, and then processing and displaying them digitally) and industrial control systems.

According to Size and Performance:

• Microcomputers:

  • Small in size and relatively low in cost.
  • Typically designed for individual use.
  • Examples include desktop computers, laptops, tablets, and smartphones.
  • Processing power varies widely depending on the specific type.

• Minicomputers:

  • Mid-range in size and processing power, between microcomputers and mainframes.
  • Designed to support multiple users simultaneously.
  • Often used in small to medium-sized businesses, departments within large organizations, and for specific applications like industrial process control.

• Mainframe Computers:

  • Large, powerful, and expensive computers.
  • Designed to handle very high volumes of data processing and support hundreds or thousands of users simultaneously.
  • Commonly used by large organizations like banks, insurance companies, and government agencies for critical applications such as transaction processing and data warehousing.

• Supercomputers:

  • The most powerful and fastest type of computers.
  • Extremely expensive and often require specialized cooling and infrastructure.
  • Used for highly complex and computationally intensive tasks such as scientific research (climate modeling, nuclear simulations), weather forecasting, and advanced engineering design.