Sea tides are the regular rise and fall of ocean water levels caused primarily by the gravitational pull of the Moon and the Sun. As the Earth rotates, different areas experience these changes, leading to high tides when water is drawn toward the gravitational source and low tides when it recedes. Tides occur in cycles, typically every 12 hours, resulting in two high tides and two low tides each day. The exact timing and height of tides can vary based on factors like the Earth's position, local geography, and weather conditions, making them an important aspect of coastal ecosystems and navigation.