Types of disc jockeys :
By definition, the role of selecting and playing prerecorded music for an intended audience is the same for every disc jockey. The selected music, the audience, the setting, the preferred medium, and the level of sophistication of sound manipulation are factors that create a number of different types of deejays. The following is a list of the most common types of disc jockeys, along with notable examples of each, listed in chronological order by birth.
 
Radio DJs :
A radio disc jockey plays music that is broadcast across radio waves, AM and FM bands or worldwide on shortwave radio stations. Radio DJs are notable for their personalities. Often due to terrestrial radio using program directors to generate the playlist, present-day radio DJs do not typically pick the music to play at stations. Emceeing is their primary duty.
   
Club DJs :
A club disc jockey is one that selects and plays music in a club setting. The setting can range anywhere from a small club, a neighborhood party, a disco, a rave, or even a stadium.
Music is the name of the game for club DJs. They focus more on the music and "beatmixing" (or "beatmatching") the music to wow their crowds. Using a seamless mix by matching the tempos of two different songs, the club DJs control the energy level of the crowd.
   
Hip Hop DJs :
 
A hip-hop disc jockey is one that selects, plays and creates music as a hip-hop artist and/or performer, often backing up one or more MCs.
   
Mobile DJs :
Historic Image - Captain PJThe mobile disc jockey is an extension of the original radio disc jockey. In its infancy, Mobile DJing was perceived as a part-time career, subsidised by a 'daytime job'; today, it is recognised a legitimate skill which leads to a marketable profession - there are many mobile DJs around the world that use this as their primary career. Even as far back as 1975, many disco companies sprung up around the world, with fleets of disco's that entertained thousands of people in remote places,
Mobile DJs travel or tour with their own sound systems and play from an extensive collection of pre-recorded music, on various media, for a targeted audience. Mobile DJs tend to work for hire at private functions such as wedding receptions, religious ceremonies, school dances; but they can occasionally be seen in bars, nightclubs, or even block parties. Unlike many club/rave DJs, mobile DJs often play more mainstream selections of music from multiple genres and they usually take requests.
 
Reggae DJs :
 
In reggae terms, the deejay is traditionally a vocalist who would rap, toast, or chat to a riddim. The term "selector" is reserved for the person who performs the traditional function of a DJ, though he does not always play the music. He often just selects it and passes it to the mixer who plays it.
 
Bedroom DJ :
A person who owns DJing equipment (i.e. turntables, mixer, CDJ, etc.) and has a passion for music, but does not play out to crowds at bars or clubs. Instead, they opt to play their music at home for their friends, record mix tapes or broadcast over the internet via audio broadcasting software, such as SHOUTcast.
   
Notable Radio DJs :
 
Christopher Stone (1882–1965), became the first disc jockey in the United Kingdom in 1927.
Martin Block (1901-1967), the first radio disc jockey to become a star, inspired the term "disc jockey".
Alan Freed (1922-1965), became internationally known for promoting African-American Rhythm and Blues music in the United States and Europe under the name of Rock and Roll.
Jimmy Savile (born 1926), British DJ and television personality, in 1947 he was the first ever DJ to use twin turntables for continuous play after he paid a local metalworker to weld two domestic record decks together.
Jack Armstrong (born 1946) worked at many radio stations over the US, including 50,00 watters like WKYC, Cleveland; WMEX, Boston; CHUM, Toronto; WKBW, Buffalo, and KFI, Los Angeles. He was once listed in the Guinness Book Of World Records as the world's fastest talking human.
Dick Clark (born 1929), host of American Bandstand, television's longest-running music/variety program, as well as a number of nationally syndicated radio shows.
Casey Kasem (born 1932), disc jockey and music historian, host of the long-running radio series American Top 40. Also the voice of Shaggy in the Scooby-Doo cartoon series.
Wolfman Jack (1938-1995), drew upon his love of horror movies and rock and roll to create his raspy-voiced, howling persona, one of radio’s most distinctive voices, and the subject of the song by the Guess Who Clap for the Wolfman which featured spoken parts by him.
John Peel (1939-2004), one of the original DJs of UK's Radio 1 in 1967, known for the extraordinary range of his taste in music, and for championing unknown musical artists.
Gary Perkins (1937-1991), a man of major importance to the industry who began his radio career in 1957 at Midland Texas' KCRS where Roy Orbison and Buddy Holly used to drop off their records. He later rose to fame in the early to mid 1970s for changing the face of country music by playing the likes of Paul McCartney, Elton John and The Eagles along side the country standards.
Howard Stern (born January 12, 1954). "King of All Media" The original "shock jock," Though controversial, he is one of the highest-paid radio personalities in the United States and the most fined personality in radio broadcast history. On October 6, 2004, Stern announced on his show that he signed a five-year deal with Sirius Satellite Radio.