SAP Internal Tables are used in ABAP programs.Its used for storing complicated data structures in working memory.Data is stored in a line by line fashion in memory and each line will have the same structure.Internal tables do all the operations like arrays in other programming languages.Data in Internal table will be deleted after the program quit.One of the main usage of Internal tables are storing the data from database tables before doing any formatting and modifications. In this page you will get some ABAP Internal table Tutorials and pdf study materials to download.

Internal table Declaration
internal table declaration in abap
Sample Program with LOOP
abap internal table with loop - sample program