Serena Jameka Williams (born September 26, 1981) is a former World No. 1 American professional tennis player who, as of November 10, 2008, is ranked World No. 2 by the Women's Tennis Association. She has won 18 Grand Slam titles: nine in singles, seven in women's doubles, and two in mixed doubles. She also has won two Olympic gold medals in women's doubles. She is the most recent player, male or female, to have held all four Grand Slam singles titles simultaneously. In 2005, Tennis magazine ranked her as the 17th-best player of the preceding forty years. She is the younger sister of a former World No. 1 professional female tennis player, Venus Williams. Serena currently resides at Ballen Isles in Palm Beach Gardens, Florida.

Williams is primarily a baseline player. Her game is built around taking immediate control of rallies with her powerful serve, return of serve, and forceful groundstrokes that can come from both the forehand and backhand wing.

Her serve is widely regarded as the best in the women's game. She is known for having a very smooth motion and her serve is one of the most highly respected on the WTA tour. For example, Lindsay Davenport has said that Williams's serve is the best serve that she has faced on the WTA tour. Williams frequently hits serves over 120 mph and often varies the placement of her serve; in 2006 at Cincinnati she struck a serve which measured at 127 mph and in 2008 at Charleston she recorded 129 mph, a speed which only two other female players have exceeded.  She can hit flat, slice, and topspin serves to both corners of the service box. Williams is capable of overpowering her opponents when returning serve, off both second and first serve.

Williams is also effective at the net, employing solid volleys (being especially effective on the drive volley) and powerful overheads. She also can produce good drop volleys, a shot that not many players use.

Although Williams's forehand is among the most powerful shots in the women's game, her backhand is considered to be one of the best, if not the best, on the Women's Tennis Association tour. Williams can often hit a winning backhand shot in any position or place on the court down the line or cross court albeit on the defence or under pressure. Williams strikes her backhand groundstroke using an open stance. She also uses the same open stance for her forehand.

Because of her aggressive style of play, Williams hits a relatively high number of unforced errors. This is tempered, however, by the fact that she typically hits more outright winners than her opponents. Other times her number of unforced errors are tempered by her powerful strokes forcing her opponents to commit errors.

Although many think of Williams as only an offensive player, she also has a good defensive game. Williams is quick around the court, and her core strength enables her to hit the ball efficiently from difficult positions. Williams has more variety in her game than the typical offensive baseline player. Although she normally dictates play from the baseline with heavy strokes, Williams occasionally slices her backhand or hits heavy topspin groundstrokes or drop shots to change the pace of the ball. (via Wikipedia)