1.      Infrastructure—The physical and hardware system components, for example, mainframes, servers, and related components and facilities.

2.      Software—The programs and operating software of a system, including operating systems, utilities, and applications (financial systems).

3.      People—The personnel involved in any aspect of operation or use of a system, for example, programmers, operators, users of the system, and management.

4.      Procedures—The programmed and manual guidelines, instructions, and steps involved in operating systems, including information technology (IT) procedures for backup and maintenance.

5.      Data—The information captured, used, and supported by a system, including files and databases, for example.

Business systems use these system components to transform data inputs into information outputs.

A system can be very simple, for example, with only one user of a payroll application based on a personal computer. Or, a system can be much more complex and sophisticated, with large numbers of users inside and outside the entity accessing many applications by the use of many computers, for example, a large banking system.