Tennis is a racquet sport played between two players (singles) or between two teams of two players each (doubles). Each player uses a strung racquet to strike a hollow rubber ball covered with felt (most of the time Optic Yellow, but can be any color or even two-tone) over a net into the opponent's court.Leading juniors are allowed to participate for their nation in the Junior Fed Cup and Davis Cup competitions as well. To succeed in Tennis often means having to begin playing at a young age. To facilitate and nurture a junior's growth in Tennis, almost all Tennis playing nations have developed a junior development system. Juniors develop their play through a range of tournaments on all surfaces, accommodating all different standards of play. Talented juniors may also receive sponsorships from governing bodies or private institutions.