Which type of device is primarily used to input text and commands into a computer?

The device primarily used to input text and commands into a computer is the keyboard. A keyboard consists of keys that represent letters, numbers, symbols, and function commands, allowing users to type directly into applications and communicate with the computer's operating system. This capability makes it essential for tasks such as writing documents, programming, and entering data.

In contrast, a monitor is an output device that displays information processed by the computer; it does not allow for text input. A mouse is mainly used for pointing, clicking, and navigating graphical user interfaces, serving as a pointing device rather than a text input method. A printer, on the other hand, is also an output device that generates physical copies of digital documents and images, without providing any functionality for inputting commands or text into the system.