Computers are essentially high-end calculators with five components: input, output, main memory, storage and a central processing unit. Computers are credited as the creation of 1940s German scientist Jon von Neumann, who built the first computer with vacuum tubes and wires. With the invention of the transistor and integrated circuits, computers have evolved into categories such as mainframes, personal computers, laptops and supercomputers. Mainframes function as one central computer feeding and receiving information to and from keyboards and monitors. Personal computers allow single users to process data. Laptops are portable incarnations of computers, and supercomputers are high-end and powerful computers used for scientific and military processing.
Computers are considered high-end calculators because they work off of binary addition. All functions of a computer--whether it's playing a video, saving information to the hard drive or connecting to the Internet--are all math-based as the processor performs binary math on every action.
Input and Output Devices
Computers work with input via devices that bring in data and information from external sources (e.g., users.) An input device is defined as any object that brings information into the computer for processing or storage. Input devices include keyboards, mice, touch-screen monitors and network cards.
Computers work with output via devices that put data out to the user from the computer. Output devices are any objects that send data from the computer to the user or another device expecting it. Output devices include printers, monitors and speakers.
Computers also work due to main memory. Without main memory, computers wouldn't be able to process the high-end math that they need to function. Main memory is the RAM that allows computers to perform and maintain the answers from their binary equation arithmetic. Main memory comes in many types (i.e., RAM, SD-RAM, DRAM) but is always volatile (it loses its values with loss of electricity).
Central Processing Unit
Computers work because of their central processing unit, which handles the path of data in computers. The CPU makes sure that print jobs go to the printer, for example, and that network communications go to the hard drive or the Internet. A portion of the CPU, called the arithmetic logic unit, also performs the simple math needed and the logic required for decision making.
Storage allows the computer to keep data for long-term periods. Where the main memory is volatile and changes with shifts of current, the storage components hold information until the user requests their deletion. Devices for storage include hard drives and optical memory devices (e.g., CDs and DVDs).