There are three forces that cause tides: The earth's rotation, the moon's gravitational pull and the sun's gravitational pull. Since water is more elastic than rock, the pull of the sun and moon on the earth causes bulging in the oceans. These bulges are tides.
The location of tides changes because the earth constantly rotates. The moon and sun pull from different directions at different times. Sometimes the moon and sun pull in the same direction, creating more extreme tides. This is called a spring tide. There are generally two high tides and two low tides during a 24 hour time period due to the earth's rotation. The strengths of tides are based on a 28 day lunar cycle.
There are other types of tides as well. A neap tide is when the moon pulls at a right angle compared to the sun's pull. This type of tide is less extreme, since the sun and moon are countering each others effects
spring tide is an extreme tide caused by the sun and the moon pulling in the same direction. It happens many times per year and has nothing to do with the spring season.
neap tide is a shallow tide caused by the sun and the moon working against each other.
ebb tide is when the tide goes from high to low tide.
flood tide is when a tide goes from low to high tide.
tidal range is the range of water level that changes due to the tide.