What is the difference between a 7 chord and a maj7 chord in music theory?

The difference between a 7 chord and a maj7 chord in Music Theory is that a 7 chord has a dominant 7th note, while a maj7 chord has a major 7th note. This distinction affects the overall sound and feel of the chord, with the maj7 chord having a more resolved and harmonically rich quality compared to the 7 chord.