COMPUTER Computer is an electronic device that accepts data, processes the data, stores data and produces the result (output).Computer is used for communication, typing, entertainment, playing of games etc. Computer is an electronic device because it made up of components which use energy called electrical energy.Computer is a system because it comprises of various parts. There are different components which makes up a computer which include keyboard, mouse, cpu, monitor, etc. Key factors are those necessary words that must be included in the definition of computer, they are vital in the definition of computer which are Electronic Device Accepts, Data Process Data, Stores Data and produces Result (Output).. Computer is classified into different classes. The classification of computer is mainly based on three classes.Classification by size Classification by type Classification by generation. CLASSIFICATION BY SIZE In the classification of computer according to its size include; Super Computer Mainframe Computer Mini Computer Micro Computer Super Computer: These are the biggest of all sizes of computer Mainframe Computer: These are the next in size of computer. Mini Computer: These are the general purpose computer. It was invented by a scientist called Kenneth W. Oben. These type of computer are also called personal computer. Mini Computer: They are the modern computer that contains microchips. E.g. robot, etc. CLASSIFICATION BY TYPE: In the classification of computer according to its type, we have; Analog computer Digital Computer Hybrid Computer Analog Computer: These are computer that has to do with our daily activities it measures values. They are computers that do not receive digital inputs. Example includes Clock, Gauge, wall clock, etc. Digital Computer: These are computers that are used for addition, subtraction, multiplication, division, etc. They are computer that receives digital inputs. Examples of digital computer include Wrist watch, calculator, etc. Hybrid Computers: This type of computer combines both activities of the digital and the analog computer. CLASSIFICATION BY GENERATIONS Computer Generations refers to the stages involve in the growth and development of computer, when each was produced and the facilities available at that period. Classification of computer according to its generations include First Generation Computer Second Generation Computer Third Generation Computer Fourth Generation Computer Fifth Generation Computer FIRST GENERATION OF COMPUTER: The first generation of computer is computer that contains vacuum tubes. It was introduce within a time interval from 1946 – 1964. Characteristics of The First Generation of Computer The first generation of computer was made up of vacuum tubes. It was large. It was slowIt produces much heat Expensive to build THE SECOND GENERATION OF COMPUTER The second generation of computer was introduced from 1967 – 1971