The most common contemporary song form is:
verse
chorus
verse
chorus
bridge
(verse)
chorus.
The other common song form is:
verse
verse
bridge
verse.
Verse: The verses all have the same melody but different lyrics that give us information about the situation, emotions, or people in the song. In the verse / verse / bridge / verse song form, the title is usually in the first or last line of each verse.
Chorus: The chorus is the section in which both melody and lyrics are repeated. The chorus lyrics give us the heart of the song. The title of the song almost always appears in the chorus section and may be repeated two or more times.
Bridge: The bridge has a different melody, lyrics, and chord progression from the verse or chorus. It provides a break from the repetition of verse and chorus and is sometimes an emotional turning point.