Racket is the standard spelling of the word. Racquet is an alternative spelling used more commonly in certain sports (squash, racquetball, badminton, tennis) and less commonly in others. While some writers, especially those outside North America, prefer the French-influenced racquet, racket is the predominant spelling by a large margin. Similarly, while some believe that racket came about as a misspelling of racquet, racket is in fact the older spelling: it has been in use since the 16th century, with racquet only showing up later in the 19th century as a variant of racket.
The player who would normally be serving after 6–6 is the one to serve first in the tiebreak, and the tiebreak is considered a service game for this player. The server begins his or her service from the deuce court and serves one point. After the first point, the serve changes to the first server's opponent. Each player then serves two consecutive points for the remainder of the tiebreak. The first of each two-point sequence starts from the server's advantage court and the second starts from the deuce court. In this way, the sum of the scores is even when the server serves from the deuce court. After every six points, the players switch ends of the court; note that the side-changes during the tiebreak will occur in the middle of a server's two-point sequence. At the end of the tiebreak, the players switch ends of the court again, since the set score is always odd (13 games).
Not all tennis racquets are meant to be used on all different kinds of court surfaces. You will have to pay attention to this when shopping for a new tennis racquet. It will probably not matter what tennis racquet you use on any surface if you are a novice tennis player but that is hardly the case if you are an intermediate or above tennis player.Some racquets are of such high quality that you can use them on any type of surface but others work best on specific types of tennis court surfaces. This will usually be noted either on the packaging description of the tennis racquet or you can most likely look it up on the manufacturer’s website too.