The document discusses different types of computers and their uses. It describes how computers are now ubiquitous in many devices like cars, home appliances and workplaces. It then defines computers and their basic components like hardware, software, data and users. The document categorizes computers based on their use, power, price and type. It explains different types of computers like desktops, laptops, tablets, smartphones used by individuals. It also discusses computers used in organizations like servers, mainframes and supercomputers. Finally, it describes the essential computer hardware components like processors, memory, input/output devices and storage devices.