What does Sharapova mean by wild card?

Simply put, "wild cards" are issued to those players who are not qualified for the competition. The organizer of the competition invites one or more players or teams to participate in the competition according to the ranking of players, and gives them wild card qualifications. These opportunities are usually given to young players who are not ranked high enough, some outstanding players and top players who have not yet recovered their high rankings, or star players who have not yet signed up, and some players from the host country. Since Shawa came back this year, she has won many wild cards, as well as the China Open and tianjin railway station. Fortunately, Tianjin entered the final. Come on!