The word datatype is self describing.It is a type (kind) of data. You have the ability to create your own 'composite' types specific to your needs. Though an advanced feature, it's easy to set up within your system.
An example of a Composite Type would be:CREATE TYPE recruit AS ( recruit_name string, recruit_id integer, wage_offer numeric); If you entered -or imported - the data listed above above, all 3 'fields' would be within1 column of your Table. The specific elements would be 'sub-fields' of the Column. You won't need to type the SQL above. Just a couple of mouse clicks will be required.
From the Menu, Select New --> TypeName it, add a description, and click AddNew for each 'subfield'.
Click Save. You're done. Next time you create a Table, your new datatype will be available from the Drop down list of Column types.
Whenever you create any new content, make it a habit to check your work immediately after. It's easier to fix mistakes while they are still fresh. If you get stuck, ask an expert.