Terminals are computer programs which provide text-based interfaces for computers to interact with the system. They provide the user with a command prompt where commands can be entered. The commands typed into the terminal are used by the operating system (OS) of the computer to run various functions such as running a program, making changes to the computer configuration settings, or deleting files and folders. Terminals may be either physical or virtual, and they allow users to access remote computer networks or servers that may not be directly accessible through the computer's graphical user interface (GUI).