1. Computer Generations

4. First Generation - 1940-1956 The first generation computers used vacuum tubes for circuitry and magnetic drums for memory , and system build-up to entire rooms. They were very expensive to operate and in addition to using a great deal of electricity, generated a lot of heat, which was often the cause of malfunctions. First generation computers relied on machine language , the lowest-level programming language understood by computers, to perform operations, and they could only solve one problem at a time. Input was based on punched cards and paper tape, and output was displayed on printouts. The ENIAC and UNIVAC computers are examples of first- generation computing devices. The UNIVAC was the first commercial computer delivered to a business client to the U.S. Census Bureau in 1951.

5. ENIAC

6. UNIVAC

8. Magnetic drum memory A magnetic drum is a metal cylinder coated with magnetic iron-oxide material on which data and programs can be stored. Magnetic drums were once used as a primary storage device then used as auxiliary storage devices. The tracks on a magnetic drum are assigned to channels located around the circumference of the drum. A single drum can have up to 200 tracks. As the drum rotates at a speed of up to 3,000 rpm, the device's read/write heads deposit magnetized spots on the drum during the write operation and sense these spots during a read operation. This action is similar to that of a magnetic tape or hard drive. The drum is permanently mounted in the device and able to retrieve data at a quicker rate than tape or disk devices.

11. Second Generation - 1956-1963 Second generation of computer was based on Transistors replaced vacuum tubes after its inventions in 1947. The transistor was far superior technology to the vacuum tube, allowing computer circuitry to become smaller, faster, cheaper, more energy-efficient and more reliable than their first-generation technology. Though the transistor still generated a great deal of heat that subjected the computer to damage, yet it was a vast improvement over the vacuum tube. Second-generation computers still relied on punched cards for input and printouts for output.

15. Magnetic Core Technology Magnetic core memory is an early form of RAM computer memory. It uses small magnetic ceramic rings , the cores , through which wires are threaded to store information via the polarity of the magnetic field, such memory is called core memory or core . Magnetic core memory technology was the application of PHYSICS branch of Electromagnetism .

18. Third Generation - 1964-1971 Third Generation of computers are based on Integrated Circuits (ICs), the invention of the Integrated Circuit was the hallmark of the third generation of computers. Transistors were miniaturized and placed on silicon chips, which drastically increased the speed and efficiency of computers. Instead of punched cards and printouts, users interacted with keyboards and monitors and interfaced with an Operating System, which allowed the device to run many different applications at one time with a central program that monitored the memory. Computers for the first time became accessible to a mass audience because they were smaller and cheaper than their earlier generations.

20. Integrated Circuits An Integrated Circuit (IC) which contains thousands of transistors is a small electronic device made out of a semiconductor material, the first IC was developed in the 1950s by Jack Kilby and Robert Noyce. This semiconductor ICs are used for a variety of devices, including microprocessor, audio and video equipment, and automobiles. Integrated circuits are often classified by the number of transistors and other electronic components they contain: SSI (small-scale integration): Up to 100 electronic components per chip MSI (medium-scale integration): From 100 to 3,000 electronic components per chip LSI (large-scale integration): From 3,000 to 100,000 electronic components per chip VLSI (very large-scale integration): From 100,000 to 1,000,000 electronic components per chip ULSI (ultra large-scale integration): More than 1 million electronic components per chip.

21. Fourth Generation - 1971-Present: Microprocessors The microprocessor brought the fourth generation of computers, as thousands of integrated circuits were built onto a single silicon chip. What in the first generation filled an entire room could now fit in the palm of the hand. The Intel 4004 chip, developed in 1971, located all the components of the computer - from the Central Processing Unit and memory to input/output controls - on a single chip. In 1981 IBM introduced its first computer for the home user, and in 1984 Apple introduced the Macintosh. Microprocessors also moved out of the realm of desktop computers and into many areas of life as more and more everyday products began to use microprocessors. As these small computers became more powerful, they could be linked together to form networks, which eventually led to the development of the Internet. Fourth generation computers also saw the development of GUIs, the mouse and handheld devices.

27. Fifth Generation - Present and Beyond: Artificial Intelligence Fifth generation computing devices is based on advance and state–of-the-art technology of processors with other features of Artificial Intelligence, Its some applications are; Voice recognition, Parallel Processing Auto Systems Quantum Computation Nanotechnology GPS, GIS Robotics Grid computation The goal of fifth-generation computing is to develop devices that respond to natural language input and are capable of learning and self-organization.

30. Voice Recognition This is one of the field of computer science that deals with designing computer systems that can recognize spoken words, this means that system recognized voice will be matched with expert systems and respond as per received voice instructions. The most powerful system can recognize thousands of words. Practical voice recognition systems used in computer dictionaries, digital libraries, customer services and training session.

31. Robotics This field of computer science and engineering concerned with creating robots, devices that can move and react to sensory input. Robotics is also branch of artificial intelligence. Robots are widely used in factories to perform high-precision jobs such as welding and riveting. They are also used in special situations that would be dangerous for humans -- for example, in cleaning toxic wastes or defusing bombs. Though great advances have been made in the field of robotics but still not very useful in everyday life.

32. Nanotechnology Nanotechnology , is the deals with control of matter of atomic and molecular substances. Generally nanotechnology work with structures of the size 100 nanometers or even smaller, and involves developing materials or devices within that size. Nanotechnology is very diverse fied, ranging from extensions of conventional physics components to molecular self-assembly. This technology making possible by developing new materials with dimensions on the nano-scale, even to speculation on whether we can directly control matter on the atomic scale. Nanotechnology has the potential to create many new materials and devices with wide-ranging applications, such as in medicine, electronics, energy production and atomic research.

33. Quantum Computation It is branch of Physics dealing with the properties of Atoms or nuclei applications that allow them to work together as quantum bits, or qubits , using computer's processor and memory by interacting with each other, qubits can perform certain calculations exponentially faster than conventional computers. Qubits do not rely on the traditional binary 0 and 1 numbers but quantum computers encode information as a series of quantum-mechanical states such as spin directions of electrons or polarization of a photons. Quantum computing has the potential to be much more powerful than a classical computer of the same size, using only a single processing unit, a quantum computer can naturally perform many operations in parallel.

34. Parallel Processing In computers, parallel processing is the processing of program instructions by dividing them among multiple processors with the objective of running a program in less time. In the earliest computers, only one program ran at a time, The computer would start an I/O operation, and while it was waiting for the operation to complete. Multitasking is practical application of parallel processing.

35. Grid computation Grid computing is the act of sharing tasks over multiple computers. Tasks can range from data storage to complex calculations and can be spread over large geographical distances. These computers join together to create a virtual (network) super computer, Networked computers can work on the same problems, traditionally reserved for supercomputers, and yet this network of computers are more powerful than the super computers built in the seventies and eighties. Modern supercomputers are built on the principles of grid computing.

36. Mobile Computing Mobile computing can be describing as the ability to use technology while moving, with the help of this technology device can work in any piece of earth. Many types of mobile computers have been introduced since the 1990s, including the: Wearable computers Personal Digital Assistant Enterprise Digital Assistant Smart Phones Ultra-Mobile PC are the best examples of mobile computing.

37. GIS A geographic information system (GIS) integrates hardware, software, and data for capturing, managing, analyzing, and displaying all forms of geographically referenced information. GIS allows us to view, understand, question, interpret, and visualize data in many ways that reveal relationships, patterns, and trends in the form of maps, globes, reports, and charts. A GIS helps you answer questions and solve problems by looking at your data in a way that is quickly understood and easily shared. GIS technology can be integrated into any enterprise information system framework.

38. GPS The Global Positioning System (GPS) is a navigation and accurate-positioning technology, developed by the Department of Defense in 1973 , GPS was originally designed to assist soldiers and military vehicles, planes and ships in accurately determining their locations world-wide. Today, the use of GPS have been extended to both commercial and scientific applications. Commercially, GPS is used as a navigation and positioning tool in airplanes, boats, cars, and for almost all outdoor recreational activities such as hiking, fishing, and kayaking. In Science, GPS plays an important role in the earth sciences, meteorology, weather forecasting, and geologists can use it as a highly accurate method of surveying and in earthquake studies to measure motions and shocks during and in between earthquakes.