In volleyball, how is a "block" defined?

A "block" in volleyball is defined as an attempt made by one or more front-row players to intercept a ball that is coming from an opposing team's attack at the net. This defensive maneuver is executed by jumping and extending the arms above the net to prevent the ball from crossing into their side of the court. The primary goal of the block is to challenge the attack, potentially redirect the ball, and to protect the court from the opponent's attacks.

This is fundamentally a key part of defensive strategy in volleyball, as it not only aims to stop the ball but also can create opportunities for subsequent plays. The nature of a block requires players to be skillful and timing-aware, ensuring they make contact with the ball to defend against spikes or attacks effectively. The importance of blocking extends beyond just stopping the ball; it can also energize the team's defense, providing momentum and psychological advantages during a match.

The other options do not align with the definition of a block. A successful serve, receiving a serve, and changing player positions pertain to different aspects of the game and do not encapsulate the specific action of intercepting an attacking ball at the net.