A tide is the regular rise and fall of sea levels caused by the gravitational pull of the Moon and the Sun on the Earth's oceans. This phenomenon occurs in a predictable cycle, typically twice a day, resulting in high and low tides. The strength of the tide can vary based on the alignment of the Earth, Moon, and Sun. Tides are influenced by several factors, including the shape of the coastline, ocean floor topography, and local weather conditions. Coastal areas experience different tidal ranges, which can affect marine life and human activities such as fishing and boating. Understanding tides is essential for navigation and coastal management.