Causes of tides 1

Tides are the vertical rise and fall of the surface of a body of water, caused primarily by the gravitational attraction of the moon and to a lesser extent, the sun.
The rotation of the earth is the primary cause of two high tides and two low tides per day, also called semi diurnal tide, experienced in most parts of the world.
Some locations on earth have only one high tide and one low tide per day – called diurnal tide – due to the path of the moon and other geographical factors.
A few other places experience a combination of diurnal and semi diurnal tides, called mixed tides.
The difference in height between a high tide going to a low tide, or a low tide going to a high tide is called the tidal range.
The rising tide is called the flood tide and the falling tide is called the ebb tide.