 Hello learners, I am Dr. Sudeesh Rupa-Pharali and in this video I am going to talk about Flin's classification of computer architecture. This is a part of the topic Introduction to Computer and part of the course Computer Fundamentals. Computer architecture has been classified into four categories according to Flin's classification which is based upon the number of concurrent instruction or control streams and data streams that are available in the architecture. There are four categories in Flin's classification of computer architecture. The four categories are single instruction stream and single data stream that is SISD, single instruction stream and multiple data stream that will be SIMD, multiple instruction streams but single data stream that will be MISD and multiple instruction stream and multiple data streams that will be MIMD. Let us look at the first architecture that is the single instruction stream and single data stream or SISD. This is a sequential computer which exploits no parallelism in either the instruction or the data streams. There is a single control unit which fetches single instruction stream from memory. The control unit then generates appropriate control signals to direct the single processing element to operate on the single data stream that is one operation at a time. Examples of SISD architecture are the traditional uniprocessor machines like older personal computers. The next architecture is a single instruction stream but multiple data streams or SIMD. Here it includes computers which exploits multiple data streams against the single instruction stream to perform operations in a parallel manner. For example an array processors or graphic processing unit. The next architecture is the multiple instruction stream single data stream or MISD architecture. Here multiple instructions operate on one data stream. This is an uncommon architecture which is generally used for fault tolerance. The space subtle flight control computer is an example of this architecture. The fourth and the last architecture is the multiple instruction stream multiple data stream or MIMD. Here multiple autonomous processors simultaneously execute different instructions on different data. MIMD architectures include multi-core superscalar processors and distributed systems using either one shared memory space or a distributed memory space. Let us look at the different applications of computers. Computers are used in various areas like science, education, health and medicine, engineering and entertainment. In the areas of science, computers are used to carry out their research works based on complex computations. Now this is done because of the computer's fast speed and accuracy. In the area of education, computers are used nowadays in schools and colleges and this is done to make learning more interesting. In the areas of health and medicine also, computers are rapidly being used. This is done starting from diagnosing illness to monitoring a patient's status. These computers are used for surgery in pathological analysis in CAT scans, MRI scans and many other uses. In engineering also, computers are used. Engineers and architects are using computers in designing machineries and drawing design layouts. Computers are also increasingly used in the field of entertainment. With the use of multimedia facilities, computers are now greatly used in the entertainment industry. Computers are used to bring in spatial effects on images, sound and animation. Some other areas of computer applications are communication, business and banking. Computer network and the internet have brought about drastic changes in the communication system. Through email, it is possible to send messages and reports very fast from one person to another or to a group of persons. In business and banking too, computers have a very large role. Nowadays, more and more persons are coming up and using the online internal banking facility. Also, in order to deposit or withdraw cash from bank, we can now use ATM services which are available 24 hours a day. Through the computer networks, among different branches of a bank, inter-branched transactions can also be carried out without delay. Thank you for listening to this video.