The oceanic water twice rises towards the coast and twice comes down towards the sea. This up and down movement is called the tide.
Reasons For Tide: Tides take place because of the attraction of the sun and moon. The attraction of the sun is many times more than the moon attraction but because the moon is nearer to earth so it creates more effect on the oceanic water i.e. why the moon attraction is considered as the main source of tides.
High Tides: High tide means when the wave in the ocean rises very high, it happens when the sun and moon both pull the ocean water upwards. High tides take place only on high moon days or no moon days. Because on both these days sun, moon and earth are in a straight line, and the waves in the ocean are more than what they normally are.
Low Tides. On the 7th and 21st day of full moon night both moon and sun make 90° angle with the earth. So both these pull the ocean water towards each other. Because the moon is closer to the earth, the water rises towards the moon, but the opposite power of the sun almost cancels the effect of moon power. So the rise of the sea waves is reduced to a low level. It is called low tides.
