 Hello dear learners. In this video I am going to talk about the different generations of computers and this is part of the topic Introduction to Computer and part of the course Computer Fundamentals. The history of computer development is often considered with reference to the different generations of computing device. Each generation of computers is characterized by a major technological development that has fundamental change the way computers operate, resulting in increasingly smaller, cheaper and more powerful and more efficient and reliable devices. There are five generations of computers. Let us look at them. Let us look at the first generation of computers. These generations started in 1945 and lasted till 1955. There are various characteristics of the first generation computers are, number one, that the become tubes were used. The computers that were used in this generation were very large in size. They consumed more power and gave limited performance. Also the cost of these computers were very high. The computers in this generation used assembly language to prepare the programs. Also punch cards and paper tape were invented to feed the programs and data and to get the result in this generation of computers. Magnetic tape or magnetic drum were also used as secondary memory devices. This type of computers were mostly used for scientific computations. We have the second generation of computers. The second generation lasted from 1955 to 1965. Some examples of computer in this generation are IBM 7030, Digital Tata Corporation's PDP 158 Honeywell 400. Let us look at the characteristics of the second generation of computers. Now the major change was that the registers were used in place of vacuum tubes in the second generation of computers. These were now smaller in size and consumed less power and gave better performance. Also the cost of the computers in this generation was considered lower. Magnetic ferrite code memories were used as main memory. Also many high-level languages such as Fortan, Cobel etc were used in this generation of computers. Separate input output processors were also developed that could operate in parallel with the CPU. Now second generation computers were used in business, industry and commercial organizations. The third generation of computers started from 1965 and lasted till 1975. Example of computers in this generation are 360 main frame from IBM. Now the main characteristics of this generation of computers are that ICs were used in place of transistors. Small-scale integration and medium-scale integration technology were implemented in CPU and input output processors. These computers were smaller and gave better performance with comparatively lesser cost and faster processors. Operating system software were first developed in this generation of computers. Catchy and virtual memories were also introduced. Database management, multi-user application, online systems like closed-rope process control, airline reservation, interactive query systems emerged in this generation of computers. The fourth generation started in 1975 and lasted till 1989. Example of computers in the fourth generation are Intel's 8080 Motorola's 68000 Apple II and Cray. Let us look at the characteristics of the computers in the fourth generation. Microprocessors were used as CPU complete processors and a large section of main memory could be implemented in a single chip. VLSI design was implemented as tens of thousands of transistors could be placed in a single chip. CRT screen, laser and inkjet printers, scanners were developed. Semiconductor memory chips were used as the main memory in this generation. Secondary memory was composed of hard disk, floppy disk and magnetic tips but also used as backup memory. Parallelism, pipelining, catchy memory and virtual memory were also applied in a better way. Concepts of local area networks and wide area networks were developed. CR language and the Unix operating system was introduced in this generation. Graphical user interface or GUI was also introduced in the fourth generation. The fifth generation is the last latest generation of computers and it started in the year 1989. Some of the examples of fifth generation of computers are IBM notebooks, Pentium PCs, Sunworks Sessions etc. Let us look at the characteristics of the fifth generation of computers. In this generations computers are based on artificial intelligence. Here computers use extensive parallel processing, multiple pipelines and multiple processors. Massive parallel machines and extensively distributed systems connected by communication networks fall in this category. Ultra large scale integration or ULSI technology has been introduced in this generation of computers. Super scalar processors, vector processors, FIMD processors and many other processors have been developed in this generation of computers. Thank you for listening to this video.