ABAP variables definition

You can declare variables statically using the following statements:

DATA: To declare variables whose lifetime is linked to the context of the declaration

STATICS: To declare variables with static validity in procedures

CLASS-DATA: To declare static variables within classes

PARAMETERS: To declare elementary data objects that are also linked to an input field on a selection screen

SELECT-OPTIONS: To declare an internal table that is also linked to input fields on a selection screen

RANGES: To declare an internal table with the same structure as in SELECT-OPTIONS,but without linking it to a selection screen.