The five generations of computers are characterized by electrical current flowing through the processing mechanisms listed below: The first within vacuum tubes The second within transistors The third within integrated circuits The fourth within microprocessor chips The fifth unveiled smart devices capable of artificial intelligence.

First Generation of Computers: 1940s -1950s: (Vacuum Tubes and Plug boards) Characteristics of 1st Generation Computers They: Used vacuum tubes for circuitry Electron emitting metal in vacuum tubes burned out easily Used magnetic drums for memory Were huge, slow, expensive, and many times undependable Were expensive to operate Were power hungry Generated a lot of heat which would make them malfunction Solved one problem at a time Used input based on punched cards Had their outputs displayed in print outs Used magnetic tapes Used machine language Had limited primary memory Were programming only in machine language

Second Generation of Computers: 1950s -1960s: (Transistors and Batch Filing) Characteristics of 2nd Gen Computers They: Used transistors Faster and more reliable than first generation systems Were slightly smaller, cheaper, faster Generated heat though a little less Still relied on punch cards and printouts for input/output Allowed assembly and high-level languages Stored data in magnetic media Were still costly Needed air conditioning Introduced assembly language and operating system software

Third Generation of Computers: 1960 - 1970s (Integrated Circuits and Multi-Programming) Characteristics of 3rd Gen Computers They: Used ICs Used parallel processing Were slightly smaller, cheaper, faster Used motherboards Data was input using keyboards Output was visualized on the monitors Used operating systems, thus permitting multitasking Simplified programming languages i.e. BASIC The next generation of mainframes and supercomputers took advantage of integrated circuits (IC). The Sigma 7 (1966) mainframe, and IBM-360 (1964) and CDC 8600 supercomputers (1969) were examples of these systems. Other examples of third generation computers: IBM-360 Fourth Generation of Computers: 1970s to Present (The Microprocessor, OS and GUI) Characteristics of 4th Gen Computers They: Used CPUs which contained thousands of transistors Were much smaller and fitted on a desktops, laps and palms Used a mouse Were used in networks Were cheap Had GUI Were very fast Register over 19 billion transistors in high-end microprocessors (Compare with 2,300 in Intel 4004) The fourth generation of mainframes and supercomputers evolved to powerful systems: IBM z9 (2005), z10 (2008) and z13 (2015) are examples of mainframes. Fifth Generation of Computers: The Present and The Future Fifth generation computing is built on technological advancement gained in the previous computer generations. It is meant to headline the 4th Industrial Revolution (4IR). The implementation is designed to improve human and machine interaction by harnessing human intelligence and taking advantage of the large data that has accumulated since the dawn of the digital age. It is viewed as the cyber-physical system and arises from the theory, concept and implementation of artificial intelligence (AI) and machine learning (ML). AI and ML may not be the same but are used interchangeably to mean the science of crafting devices and programs which are intelligent enough to interact with humans, other computers, the environment, and programs, by mining big data to achieve set goals. The proliferation of computing devices with the possibility they can self-learn, respond and interact in normal and probably different ways, based on acquired experience and environment, has also given momentum to the Internet of Things (IoT) concept. At their peak and with the right algorithms, computers will probably exhibit and process quite high levels of deep learning from which, humans too, can. Many AI projects are already being implemented while others are still in developmental stages. Pioneers in accelerating AI include Google, Amazon, , Apple, Facebook and Tesla. The initial implementations are now seen on smart home devices which are meant to automate and integrate activities in the house though audio/visual devices, and self-drive cars which are already gracing the roads.