The 4x400 metres relay is a track and field event where four runners each complete a 400-metre lap. Teams consist of four athletes, and each runner passes a baton to the next after finishing their lap. The race is typically run on an outdoor track and is known for its combination of speed and endurance. Each team starts in designated lanes, and the race begins with the first runner. The baton must be passed within a specific exchange zone, which is 20 metres long. The team with the fastest overall time wins the race, making it a thrilling conclusion to many track meets.