A buffer is an electronic circuit that serves to preserve the strength and integrity of an audio signal, protecting it against loss of quality.

Think of an audio signal (like that of a guitar) as a runner. If it has to run a long distance (long cables) or pass through many obstacles (multiple effects pedals), it will tire and lose energy, resulting in a weak, lifeless, and dull sound.

A buffer acts as a "boost station". It takes the original signal, creates an identical and strong copy of it, and sends it forward with renewed energy.

Its main function is to isolate the signal from the source (the guitar) from the "loading" effects caused by the impedance of subsequent equipment in the chain. Buffers are essential in pedalboards with many pedals (especially those that are not true bypass) or when using very long cables, as they ensure that the original tone of the instrument reaches the amplifier intact. Many pedals (such as those from the Boss brand) already have a built-in buffer.