KG meaning in General ?

The King's Gambit is a chess opening that begins with the moves:

White offers a pawn to divert the black e-pawn. If Black accepts the gambit, White has two main plans. The first is to play d4 and Bxf4, regaining the gambit pawn with central domination. The alternative plan is to play Nf3 and Bc4 followed by 0-0, when the semi-open f-file created after a pawn push to g3 allows White to attack the weakest point in Black's position, the pawn on f7. Theory has shown that, in order to maintain the gambit pawn, Black may well be forced to weaken the kingside with moves such as ...g5 or odd piece placement (e.g. ...Nf6–h5). A downside to the King's Gambit is that White weakens their own king's position, exposing it to the latent threat of ...Qh4+ (or ...Be7–h4+). With a black pawn on f4, White cannot usually respond to the check with g3, but if the king is forced to move then it also loses the right to castle.

The King's Gambit is one of the oldest documented openings, appearing in one of the earliest chess books, Luis Ramírez de Lucena's Repetición de Amores y Arte de Ajedrez (1497). It was examined by the 17th-century Italian chess player Giulio Cesare Polerio. The King's Gambit was one of the most popular openings until the late 19th century, when improvements in defensive technique led to its decline in popularity. It is infrequently seen at master level today, as Black has several methods to gain equality, but is still popular at amateur level.