Wiktionary
n. A category of music including hip-hop, R&B, and other primarily African-American genres.
Wikipedia
Urban contemporary is a music radio format. The term was coined by New York DJ Frankie Crocker in the mid-1970s. Urban contemporary radio stations feature a playlist made up entirely of hip hop, R&B, pop, grime, electronic music such as dubstep, UK garage and drum and bass, and Caribbean music such as reggae, dancehall, reggaeton, zoui, bouyon, and soca. Urban contemporary was developed through the characteristics of genres such as R&B and soul. Virtually all urban contemporary formatted radio stations are located in cities that have sizeable African-American populations, such as New York City, Atlanta, Chicago, Washington, D.C., Philadelphia, Detroit, Cleveland, Cincinnati, Dallas, Houston, San Francisco, Los Angeles, Baltimore, Memphis, Boston, New Orleans, Louisville, Indianapolis, Birmingham, Columbus, Oklahoma City, and Charlotte.
The term "urban contemporary" is heavily associated with African-American music, particularly for R&B in African-American contexts. For Latin Americans, the music is more Latin urban, such as reggaeton, Latin hip hop and bachatón. Their playlists are dominated by singles by top-selling hip hop and R&B performers. On occasion, an urban contemporary station will play classic soul songs from the 1970s and early 1980s to satisfy the earlier end of the genre.
Most Urban formatted stations such as KJLH, KPRS, KMEL, KDAY, and WVEE will play gospel music or urban contemporary gospel music on Sundays.
Mainstream urban is a branch of urban contemporary, and rhythmic contemporary is also a branch.