We've already met the LONG type and found that this was the normal type for variables (see 3.1.1 Variable types).
The types INT and LIST were also mentioned.
Learning how to use types in an effective and readable way is very important.
The type of a variable (as well as its name) can give clues to the reader about how or for what it is used.
There are also more fundamental reasons for needing types, e.g., to logically group data using objects (see 9.4 OBJECT Type).
This is a very large chapter and you might like to take it slowly. One of the most important things to get to grips with is pointers. Concentrate on trying to understand these as they play a large part in any kind of system programming.
Go to the Next or Previous section, the Detailed Contents, or the Amiga E Encyclopedia.