Registered representative is the official title - along with 'account executive' - given to an individual who is licensed by industry regulatory group FINRA (formerly NASD) to sell securities to the public. 'Registered Representative' is also the name of a trade magazine (usually shortened to 'Registered Rep.') that publishes news and information relevant to these individuals.
To gain the official designation of 'registered representative' (RR), an individual most pass the federal-level Series 7 exam and the state-level Series 63 exam. According to FINRA there are about 672,000 RRs in the U.S. working for about 5,100 brokerage firms. RRs are also subject to regulation by the Securities and Exchange Commission (SEC) and the New York Stock Exchange NYSE while those who work for futures commission merchants (FCMs) are also registered with the Commodity Futures Trading Commission (CFTC).