Tides refer to the rise and fall of a body of water, most commonly seen in the oceans; caused by the interaction between the moon, sun and Earth.
Tides are greatly influenced by the gravitational pull from the moon and sun. The moon's elliptic orbit means that twice a month, the moon, sun and Earth are in direct alignment and create a combined gravitational force.
In the open ocean, the tidal force of the moon will appear as bulges of water facing the moon whereas around land mass the water can spread out onto land creating tides.
Find out more about tide times, the different types of tide and measuring the tide in the links below.
Last updated: 14 August 2013