The document discusses various aspects of fluency and stuttering. It defines fluency as smooth, continuous speech produced in an effortless manner. It describes different types of disfluencies that can occur, ranging from more typical ones like filler words, repetitions and revisions, to less typical ones associated with stuttering like part-word repetitions, prolongations and blocks. It also discusses core behaviors of stuttering versus secondary behaviors, the stuttering cycle, and how stuttering can be represented using the iceberg analogy.