Jazz music is based on the blues, which is a form of African-American music. The blues piano usually features an embellished chord progression that is played in a loose, syncopated style.
Jazz piano evolved from ragtime and stride piano styles, which were popular in the early 20th century. Jazz piano usually uses much more chromaticism than other styles of piano music, and often contains extended chords and passing tones. This genre often uses many eighth and sixteenth notes, as well as syncopation and asymmetrical phrasing.