A B-boy/break-boy (male) or B-girl/break-girl (female) is a term for a person who is devoted to hip-hop culture. The term "B-boy" has come to refer more specifically to a male who practices what the media refers to as breakdancing, i.e., an individual who has the ability to express his feelings through rhythmic dance combining a variety of dance forms with gymnastics and original body movements. These stylized movements are commonly known as "breaking" or "breakdancing," and B-boys are often called breakdancers.
There is so much more about bboying, not only must you know the foundation, the key to being a true bboy/bgirl is to know the culture, the history.