What is a hybrid SACD?

Hi guys, just purchased a Bob Rodriquez Jazz 'Corridor' cd from the local thrift store, and on the back it says 'this hybrid SACD'......., as I have never bought a cd like this before can someone please clarify for me what a hybrid cd is? The sound quality is excellent. Does that also mean a full SACD will sound even better?
Thanking you in advance.