Repeater

1. An analog device that amplifies an input signal regardless of its nature, i.e., analog or digital.

2. A digital device that amplifies, reshapes, retimes, or performs a combination of any of these functions on a digital input signal for retransmission.

Note: The term "repeater" originated with telegraphy and referred to an electromechanical device used to regenerate telegraph signals. Use of the term has continued in telephony and data communications.

Source: from Federal Standard 1037C and from MIL-STD-188