Think of buffers as radio stations, not telephone calls. You tune in a buffer through a Frame . You can have many frames open, but you can only hear one at a time. The Help pages, directory lists and info pages all open a new second frame to let you jump between the help and your work without losing your place in either frame. Expect to be confused.
Some buffers are silent.
For example, if you copy files to some other computer, there is a hidden buffer where Emacs does this transfer.