Dancing in the street. Breaking and battling
Breakdancing emerged in New York in the 1970s. The style of movement, which combines dance, gymnastics, and boxing was performed by kids, often in teams, in competitions at street corners. Breakdancing was part of the larger hip-hop culture that also incorporated rappers, DJs, and graffiti artists. The Rock Steady Crew from the Bronx was one of the first hip-hop groups and became world-famous. The group still organizes a Rock Steady Crew Anniversary every year in New York to celebrate hip-hop culture and its main focus is always a street dance competition The Anniversary attracts competitors of all different ethnic types from all over the world and over 20,000 observers. 
Hip-hop terms:
breaking/breakdancing: dancing to hip- music, often close to the ground, or even on your hands or your head
b-boy/b-girl: breakdancer
crew: breakdance team
battle: breakdance competition
MC: a rapper, someone who speaks rhythmically over a beat
DJ: someone who plays records for people to rap or dance to
scratching: when a DJ moves a record with his hand to interrupt or repeat the music
Breakdance moves
donkey: jumping onto your hands from a standing position, and then flipping back onto your feet again
flares: supporting yourself on your hands and swinging your legs round
handglide: spinning on one hand
headspin: spinning on your head
popping: making sliding movements, like a robot
windmill: spinning on your back, without using your hands