Hydraulic shock, also known as water hammer, occurs when a fluid in motion is suddenly forced to stop or change direction. This rapid change creates a pressure surge or wave within the piping system, which can lead to loud banging noises and potential damage to pipes and fixtures. The phenomenon is commonly seen in plumbing systems when a valve closes quickly, causing the water to slam against the closed valve. This pressure surge can stress pipes, joints, and fittings, leading to leaks or even ruptures if not properly managed.