Instrumental pop music that gives jazz a bad name. Only referred to as jazz because many of the people that play it are saxophone players, and as soon as something is played on a saxophone, you can automatically sell it as "jazz" to the general public because many people can't tell the difference. They simply hear something played on a saxophone and automatically categorize it as jazz.
Real jazz, on the other hand, involves things like walking bass lines, swinging rhythms, and a lot of improvisation. There are a huge amount of sub-genres in jazz: traditional jazz, swing, bebop, hard bop, cool jazz, Latin jazz, soul jazz, gypsy jazz, etc.
Person 1: I play saxophone. Most of the stuff I play is jazz.
Person 2: Oh, you mean smooth jazz, like Kenny G?
Person 1: NO! I mean real jazz, like Charlie Parker, Lester Young, John Coltrane, and Wayne Shorter.