What is the difference between a jazz bass guitar and a bass guitar?

The Jazz Bass is a bass, marketed by Fender. It has a rounder, thinner neck than the Precision bass and is famous for its fantastic sound in mediums and its strong treble.

The Jazz bass (aka J bass) was the third design launched by Leo Fender (there were two slightly different designs of Precision bass (aka P bass) prior to this) and hit the market in 1960. It was intended to be a deluxe instrument with two pickups instead of one giving a wider tonal variation and a slimmer neck making it easier to play.

The voice of the instrument is more refined than the the Precision though both are considered to be classic designs. The Jazz tends to sound a little more defined then a Precision whilst also being capable of a wider variety of tones.

The flexibility of the Jazz bass has allowed a huge variety of players to create signature tones and styles with it from the biting, mid-heavy sound of Jaco Pastorius to the fat, bassy tone of Aston Barrett from Bob Marley and the Wailers.

It is one of the three classic bass guitar designs that any professional player will have in their collection (the others being the Precision and the Musicman Stingray ... all three designed by Leo Fender).

In the opinion of many players, engineers and producers alike it is the single finest design for a bass guitar. More versatile and easier to play than a Precision whilst giving a clear tone that allows each note to be heard and sit in the mix.