King's Knight Opening: Normal Variation is a chess opening with the ECO code C44, part of the King's Knight Opening family. It goes 1. e4 e5 2. Nf3 Nc6. White opens with 1. e4 (the king's pawn) and Black answers 1... e5. After 4 moves it is White to move. 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 3. Bb5, 3. d4, 3. Bc4, 3. Nc3, 3. Be2.
chessGM has a full course for this line: open the King's Knight Opening: Normal Variation course lesson.