In truth, what is hip-hop?

“Urban youth culture associated with rap music, a fashion style, and social and political activism of inner city African American youth.”
www.african-american-art-history.com/glossary.html

“Hip hop is a cultural movement that began among urban African American and Latino youth in New York. The four main elements of hip-hop are MCing, DJing, graffiti, and breakdancing. …”
www.deejayzen.com/glossary.html

“Hip-hop… represents a complex weave of black Atlantic style and African American homespun. (…) even a sit remains a global music, it is firmly rooted in the local and the temporal; it is music about ‘where I’m from,’ and such proposes a new kind of universality” (Potter)

Tell me about hip-hop…