Main parts of a computer

A computer mainly consists of 3 parts :(1) Input Device : A input device is typically a unit used to input data into the system which can be then processed . for ex. Keyboards and mouse(2) CPU ( Central processing unit) : This is often called as the brains of the computer because all the calculations and processing's are done here. Its again divided into 3 parts(a) Arithmetic & logical unit (ALU)(b) Control unit and(c) MemoryThe control unit determines what should be processed and what should be stored in the memory. The ALU as the name suggests is mainly used to calculate and take logical decisions. The memory can again be classified into two types : RAM ( Random access memory ) and Secondary memory .RAM is a volatile memory in the sense that all information stored here will be erased the moment is switched off. Be sure to save your files every now and then to avoid lossage of data.Secondary Memory are those where all the data can be stored permanently unless a command is given to erase them. Harddisks and Floppies are the most popularly used secondary types of memory used in modern computers . We also have magnetic tapes , Zip drives or pendrives that are used for the same purpose.(3) Output Device : After the data is fed into the computer its processed in the control unit and displayed through the out put device. Monitors are the most popular forms of output devices. Its also called as the screen or console ..other forms of output devices are projectors, even a printer can be loosely called as a output device ...