When you design a Table, and enter the various Fields that will need to be filled in, you get to choose the Datatype for each field.

Datatypes allow you to tell the system what type of information is expected. Some of the most common are: Text, Numeric and Date, but there are a couple of dozen in all, providing specialised functionality.

Datatypes have three main purposes:

• They guide the user who is entering the data (so they don't enter text where you want a number, etc)
• They keep the system efficient: if you only need to store a small item, say a number, there's no point in reserving lots of space for a page full of text. Keeping things efficient not only saves space, but makes the pages appear faster.
• They provide specialist functions to make your life easier: from automatic cross-referencing to e-commerce support

For a full list of datatypes, click here (This is worth reviewing even if you are a database guru, as there are some specialised ones included which you won't have come across, used to provide efficient solutions to problems common in websites)