As previously mentioned, there are 17 data types in Dynamics NAV. Before you continue, all of these data types are explained in great detail when you go to the Help section:
Note
Detailed information about the data types in Dynamics NAV can also be found here: http://msdn.microsoft.com/en-us/library/dd301350(v=nav.70).aspx.
As a matter of fact, you can find any technical terms used in this book in the Help section or on the MSDN site, but I will lay these data types out for you as "non-programmer" as possible:
BLOB: Binary Large Objects are typically used to store any files (pictures, Word files, and so on).
BigInteger: Allows you to store numbers from -9,223,372,036,854,775,807 to 9,223,372,036,854,775,807. If your program needs this many numbers, something is wrong.
Binary: Used to store a fixed length of binary data. If you do a quick Google search, this field was discontinued in NAV2009. Going forward, it's best to ignore this data type.