The "b-boy"--a term coined by DJ Kool Herc--is short for "break boy," one who embodies all four elements of hip-hop culture: DJing, freestyling, graffiti and dancing. This is the beginning of what we know as "hip-hop dance."
Breaking arose in the late 1970s from the provocation of a rival crew--a group of b-boys--calling out another. As the DJ spun the track, introducing a breakdown in a song, one crew would interpret those "breakbeats," challenging another. The winner was whichever crew could outperform the other. Bragging rights, along with dominion over the dance floor, were paramount.
Introduced by Don Campbell in the late 1960s by mistake, locking is produced when the body hits a certain beat in the song, stopping motion suddenly when the beat hits.
Popping was introduced by the Electric Boogaloos in the 1970s on the syndicated R&B music and dance show "Soul Train." It's a way the dancer interacts with the beats--the dancer's body seems to "pop."
Hip-hop started to substantially infiltrate the mainstream dance vocabulary in the early 1990s. Its latest permutation blends traditional hip-hop dance with jazz, modern and contemporary dance styles.