If you go to a beach at the same time for two days, you will see different animals and plants in different places. The waves will be different. Each day, you will see different objects, moved by the power of the sea. If you stay at a seashore, you will notice the sea coming up to the land or moving away from the land. This movement is called the tide.
High tide is when the sea comes up towards land.
When the sea moves away from land, it is low tide. Tides are created by the moon and sun. The area of seashore that is under water at high tide and above water at low tide is the intertidal zone. Many animals and plants living in the intertidal zone can live in and out of water. Along seashores, we often see plants that live in the intertidal zone and the subtidal zone, which means the area which is not uncovered by low tide.