All computers carry out four basic functions. These are data input, processing, output and storage.
Computers are used for many things. Companies use them for managing their businesses, photographers for processing photos, authors for writing books and gamers for playing virtual reality games. Even cars, trucks and aircraft use computer technology to control their various systems. Despite this diversity, all computers perform the four basic functions of data input, data processing, data output and data storage. A computer's hardware is designed around performing these basic functions as efficiently as possible.
Input In order for a computer to perform any function, it needs data. This is typically input through a keyboard, but there are also other ways of inputting data. For example, data can be automatically fed from a LAN connection or a computer controlling a chemical process will read data sent to it from sensors in the plant. Other ways of inputting data include downloading information, such as photographs from a camera or memory card for later processing. This data is temporarily held in the computer's random access memory (RAM) so that it can be processed.
Processing Raw data in RAM needs to be processed into useful information. This is performed by the computer's processor, also referred to as the CPU. The CPU is a complicated piece of computer hardware made of thousands of tiny transistors built into a single integrated circuit and controlled by an operating system. The CPU, together with the computer's operating system and the program that's running, takes data and processes it. If working with an Excel spreadsheet, it calculates the output based on the formula programmed into the spreadsheet. During gaming, the CPU projects the game onto the monitor and interprets commands as the user operates the controller. The CPU is an amazing piece of technology that represents the processing "brains" of a computer.
Output Output can be in many forms. It may simply be a letter shown on the monitor that's printed onto paper or sent as an email attachment. Alternatively, the output can be the skill of a gamer when defeating virtual enemies or a beautifully edited photograph. When viewing videos, the output is the images seen on the monitor as well as the soundtrack played over speakers.
Storage Users often want to save the output. When a document is printed, it's saved on paper. This was how the earliest computers worked, they printed their results onto paper tape. However, this isn't convenient if the output needs to be reused as it requires the inputting of information all over again.
This is why computers have hard drives that can store outputs so it's easy to access information. Alternatively, it's possible to store music on a USB drive, take it to a friend's home and play it on their computer. There are many other ways to store information, including using external hard drives or using what are known as SSD drives that have no moving parts and are incredibly fast. Information can also be stored in the cloud using OneDrive, iCloud, Google Drive or Dropbox, which are just a few of the many online storage facilities available.