Once data has been recorded in main computer storage, it can be referenced and manipulated. It can be moved to other locations in main computer storage, used in arithmetic operations, compared to other data in storage, or otherwise be processed to prepare the desired output information. This is possible because of the ability of the computer program to direct the electronic circuitry to extract data located at a specific address and use the data for processing.
In a Figure, a segment of the operations required to produce a printed report from data contained in punched cards is shown. Under control of the computer program, the data from the input record is read into main computer storage at a specific address. The fields in the input record area are then moved to the fields in the output area. The instructions causing this to happen will reference both the address of the input fields and the address of the output fields in main computer storage. The fields in the output record area are then written on the report.
The ability to address data stored in main computer storage and process it after it is addressed form the basis of the internal operations in a computer system.