Signal buffers, also known as repeaters, are interfaces used to boost the strength of an electrical signal as it passes through a communication system. They act as a powerful amplifier that can increase the power of the original signal. Signal buffers are used to ensure that the signal travels long distances with enough strength to reach its destination without becoming distorted or weakened by noise or other factors. They can also be used to interconnect two different types of communication systems, such as one using analog technology and one using digital technology. Repeaters can be used in a variety of applications, including in telephone systems, network systems, and computer systems.