 Hello dear learners, I am Dr. Satish Truba Bharali, Assistant Professor in the Department of Computer Science and in this video, I am going to talk about the topic basic features of computer classification. This is part of the course Computer Fundamentals. There are different classifications of computers. Based on the operating principles, computers can be classified into digital computers, analog computers and hybrid computers. First of all, let us look at part as an analog computer. An analog computer is a form of computer that uses the continuously changeable aspects of physical phenomenon such as electrical, mechanical or hydraulic quantities to model the problem being solved. Next, we have the digital computer. Digital computers represent varying quantities symbolically as their numerical values change. The third one is the hybrid computers. Hybrid computers are computers that exhibit both the features of analog computers and digital computers. The digital component normally serves as the controller and provides logical operations while the analog component normally serves as a software of differential equations. Depending upon the applications, modern computers are classified as general purpose computers or spatial purpose computers. In the case of general purpose computers, these computers are designed to meet the needs of many different applications. In these computers, the instructions needed to perform a particular task are wired permanently into the internal memory. When the particular job is over, the instructions for another job can be loaded into the internal memory for processing. Whereas, in the spatial purpose computers, these computers are designed only to meet the requirements of a particular task or a particular application. The instructions needed to perform a particular task are permanently stored into the internal memory so that it can perform the given task on a single command. Computers can be classified according to their size and power into four categories. They are microcomputers, mini-computers, mainframe computers and supercomputers. Now first of all, let us look at how microcomputers work. A microcomputer uses a microprocessor as its central processing unit. Microcomputers are tiny computers that can vary in size from a single chip to the size of a desktop model. They are designed to be used by only one person at a time. Microcomputers have small to medium data storage capabilities that may range from 500 mb to 2 gb, but nowadays even more. Some of the examples of microcomputers are chips that are used in washing machines, TVs, cars and notebook and personal computers. Now let us look at the different models of a microcomputer. The first one is a personal computer or PC. The name PC was given by IBM for its microcomputers. PCs are used for word processing, spreadsheet calculations and database management. The second model is a laptop or a notebook, which are very small in size. The notebook or laptop can be folded and carried around. Most often the monitor is made of LCD and the keyboard and the system units are contained in a single box. The third model is a palm top, which is a smaller model of the microcomputer. A palm top is similar to a calculator, which is pocket size. It has a processor and a memory and a special connection to connect to the desktop PC, which can be used to transfer data. The fourth and the last one is a RISPC, which is the smallest type of microcomputer. The RISPC is something that can be worn on a wrist like a watch. It will have a processor and a memory and a wireless monitor. Now here in this slide we can see the different figures of the different models of microcomputers. We can see a personal computer. We can also see a notebook and a laptop and we can also view a part of computer. The next computer classification based on size and power is the mini-computer. The mini-computer uses a microprocessor and performs better than microcomputers. Mini-computers are comparatively larger in size and costlier than the microcomputers. These computers are also designed to support more than one user at a time. Mini-computers also possess large storage capacities and operate at a higher speed. Now let us look at some of the applications for mini-computers. Mini-computers are used when the volume of processing is large, that is, when data processing for a medium-sized organization is needed. On the right-hand side, we can see a figure of the mini-computer. These computers are also used to control and monitor production processes. They are also used to analyze results of experiments in laboratories. They are also commonly used as servers in local area networks. The third category of computer classification based on size and power is the mainframe computers. The mainframe computers are able to process large amounts of data at very high speed. These computers support multi-user facility and the number of processors varies from one to six. The cost for a mainframe computer ranges from $3,500 to many million. Mostly, mainframe computers are kept in an air-conditioned room to keep them cool. Now let us look at the applications for mainframe computers. Mainframe computers are used to process large amounts of data at very high speeds. So these kind of computers are usually used in the case of banks, hospitals, railways, etc., where we need to process large amounts of transactions and which also require massive data storage and processing capabilities. Mainframe computers are also used as controlling nodes in wide-area networks and are also used to manage large centralized databases. We have a figure of a mainframe computer on the right-hand side of this slide. The fourth category of computer classification based on size and power are the supercomputers. Supercomputer is basically a broad term for one of the fastest computers currently available. Some of the characteristics of supercomputers are that they are the most powerful computer system and usually require a large room. The minimum bird length is 64 bits and the CPU speed is around 100 million instructions per second. Supercomputers are usually equivalent to 400 general computers and they have a high cost. They are also able to handle a large amount of data, but they require high power consumption. Also, the precision is very high for supercomputers. Supercomputers have applications in the field of petroleum industry, aerospace industry and automobile industry. In the aerospace industry, supercomputers are used to simulate air flow around an aircraft at different speeds and altitudes. This helps in producing an effective aerodynamic design for superior performance. In the automobile industry, supercomputers are used to do crash simulation of the design of an automobile before it is released for manufacturing. This is done for better automobile design. Metrological centers also use supercomputers for better forecasting. Apart from this, supercomputers are also used in biomedical research and in weapons research and developments. One of the examples of supercomputers are Cray 1, Cray 2 and Paramp computers. Thank you for listening to this video.