Such computers are used as control systems for a very wide variety of industrial and consumer devices.
This includes simple special purpose devices like microwave ovens and remote controls, factory devices such as industrial robots and computer assisted design, but also in general purpose devices like personal computers and mobile devices such as smartphones.
Peripheral devices include input devices (keyboards, mice, joystick, etc.), output devices (monitor screens, printers, etc.), and input/output devices that perform both functions (e.g., the 2000s-era touchscreen).
Peripheral devices allow information to be retrieved from an external source and they enable the result of operations to be saved and retrieved.
The abacus was initially used for arithmetic tasks.
The Roman abacus was developed from devices used in Babylonia as early as 2400 BC.
The Internet is run on computers and it connects millions of other computers.