12 Bar Blues is a pattern of chords which repeats every 12 bars. There are hundreds of well known songs based on this chord progression, i.e., they contain basically the same chords in the same order. 12 Bar Blues is commonly used in Rock music and is the basis of Blues music. Some well known Rock and Roll songs which use this 12 bar chord pattern are:
The following 12 Bar Blues is in the key of C major, and uses some of the chords you have learned so far. When a song is said to be in the key of C major, it means that the most important chord (and usually the first chord) is the C chord.
This pattern of chords will probably sound familiar to you.