Reverb is not a distinct repeat; it is a "cloud" of sound. It is the ambiance that remains after the initial sound stops. It provides the "body" and "presence" of a sound. Without reverb, a sound is described as "dry"—it sounds close, dead, and unnatural to our ears, much like listening to someone speaking in an anechoic chamber (a room designed to absorb all sound).
The terms "echo" and "reverb" are often used interchangeably, but they represent two distinct ways sound behaves when it bounces off surfaces. While both involve reflections, the key difference lies in the of those reflections. 1. Echo: The Distinct Repeat echo and reverb