The move "E2-E4" refers to a common opening move in the game of chess. It involves advancing the pawn in front of the king's bishop two squares forward from the E2 square to the E4 square. This move helps control the center of the board and opens lines for the queen and bishop to develop. "E2-E4" is often associated with various opening strategies, including the King's Pawn Opening and the Italian Game. It is popular among players of all levels due to its aggressive nature and potential for quick development of pieces.