Jazz dance has two meanings, depending on the era. Both forms are related by evolution.
From ? until 1955, jazz dance meant tap dance, because jazz was the music and tap was the main performance dance of the era. See Tap dance.
After 1955, jazz dance evolved into the smooth, modern Broadway style that is taught today.
Another essential root to all jazz dance is the afro-american culture from the late 1800 up till the mid 1900. Pioneers such as Kathrine Dunham took the essence of caribbean traditional dance and made it into a performing art.
"Tap dancing" had it's roots mainly from the "Irish" folk dance tradition.
During the early 1900s, these two dance forms mixed with the rebellion against ballet developed into what we today call jazz dance, or jazz ballet.
An early popular "jazz dancer" was vaudeville star Joe Frisco in the 1910s. He danced in a loose-limbed style close to the ground, with eccentric steps, and juggled his derby and cigar.
Jazz dance is a form of dance commonly used in Broadway shows and movies. Jazz is a less serious looking, looser kind of dance compared to ballet, for instance. Even though jazz dancing might look easy and fun when the dancers do it, most times the dancers have to be in really good shape, and practice sometimes six hours a day. Some traditional musical jazz numbers are
"All That Jazz" and "Chicago".
Both Jazz dance and modern dance technics are based on the basics of the old ballet tradition, even though both forms where considered to rebellions against it. To excell in jazz dance, the dancer must master both moderne dance and ballet technics.
In jazz dancing the movements are big and exaggerated and there is usually an attitude the dancer conveys to the audience. The attitude would depend on the dance. For example in a modern number like "Livin' La Vida Loca", the dancer would probably be happy, and look like they were at a party having a really rockin' time. That would give the dance a profesional look. Jazz dancing is also used in modern dancing as on MTV. Las Vegas showgirls are also jazz dancers.
Just about every dance school teaches jazz, as it is the most popular danceform for amateur dancers.
The essence of jazz dance is entertainment to the people, an eatable form of dancing which is easy to understand for anyone seeing it. As the famous choreografer and pioneer Alvin Ailey said "The dance came from the people, and should always be given back to the people".
