blues is for alcohol, jazz is for heroin
Jazz = complex harmonics and improv
Blues = form of jazz with typically 12-bar progression
Blues were a type of folk song that originates from black Americans. Basically the Blues are venting or struggle music from America - These developed in relation to Black Spirituals which were handed down to the ancestors of black slaves.
When it came time for record labels to exploit a certain class, they found that blues hit much more with white audiences than spirituals and decided to record blues' songs to fill vinyl's to print off during the era of recording.
Blues is characterized by its repeating structure and it's passionate improv along a repeating structure - notably the 12 bar blues.
Jazz was born out of this improving technique over blues structures, but was combined with the bigger bands in new orleans, and dropped the "struggle" aspect of blues. over time Jazz deviates from Blues by focusing more on the improv aspects of the music, and adding more intricate chording over time as opposed to blues.