Italian Game: Evans Gambit Accepted is a chess opening with the ECO code C51, part of the Italian Game family. It goes 1. e4 e5 2. Nf3 Nc6 3. Bc4 Bc5 4. b4 Bxb4. White opens with 1. e4 (the king's pawn) and Black answers 1... e5. After 8 moves it is White to move. After the last move Black is a pawn ahead in material. The lesson on the board explains every move of the line and lets you play it yourself; it is free.
In chessGM's opening book this position continues with 5. c3.
After 1.e4 e5 2.Nf3 Nc6, White plays 3.Bc4, aiming the bishop at the weak f7 pawn. It teaches quick development and fast castling.
chessGM has a full course for this line: open the Italian Game: Evans Gambit Accepted course lesson.