Channel or pre-chorus are probably the two most common names for this part of a song. It can also be called a lift or a lead-in. What is it exactly and what purpose does it serve?
All of these names are actually quite descriptive of this brief section of a song that sits between the verse and the chorus … it lifts from the verse to the chorus, or it serves as a channel from the verse to the chorus. Musically, it’s designed to add excitement or to shift the song into a higher gear as listeners approach the chorus. Lyrically, it provides an opportunity for the songwriter to wrap up the general information of the verse and make the transition into the specifics of the chorus. Just as the music of the channel heightens the action or tension of the song, so should its lyrics.
There are no rules of course, but generally a channel is only one or two lines long. The lyrics for the channel may be different for each verse or they may be repeated with each verse.