Information systems

The term information system (IS) sometimes refers to a system of persons, data records and activities that process the data and information in an organization, and it includes the organization's manual and automated processes. Computer-based information systems are the field of study for information technology, elements of which are sometimes called an "information system" as well, a usage some consider to be incorrect.

The term "information system" has different meanings:

In computer security, an information system is described by three objects:

Structure:

Repositories, which hold data permanently or temporarily, such as buffers, RAM, hard disks, cache, etc. Interfaces, which exchange information with the non-digital world, such as keyboards, speakers, scanners, printers, etc. Channels, which connect repositories, such as buses, cables, wireless links, etc. A Network is a set of logical or physical channels.

Behavior:

Services, which provide value to users or to other services via messages interchange. Messages, which carries a meaning to users or services. In geography and cartography, a geographic information system (GIS) is used to integrate, store, edit, analyze, share, and display georeferenced information. There are many applications of GIS, ranging from ecology and geology, to the social sciences.

In knowledge representation, an information system consists of three components: human, technology, organization. In this view, information is defined in terms of the three levels of semiotics. Data which can be automatically processed by the application system corresponds to the syntax-level. In the context of an individual who interprets the data they become information, which correspond to the semantic-level. Information becomes knowledge when an individual knows (understands) and evaluates the information (e.g., for a specific task). This corresponds to the pragmatic-level.

In mathematics in the area of domain theory, a Scott information system (after its inventor Dana Scott) is a mathematical 'structure' that provides an alternative representation of Scott domains and, as a special case, algebraic lattices. In mathematics rough set theory, an information system is an attribute-value system.

In sociology information systems are also social systems whose behavior is heavily influenced by the goals, values and beliefs of individuals and groups, as well as the performance of the technology.

In systems theory, an information system is a system, automated or manual, that comprises people, machines, and/or methods organized to collect, process, transmit, and disseminate data that represent user information.

In telecommunications, an information system is any telecommunications and/or computer related equipment or interconnected system or subsystems of equipment that is used in the acquisition, storage, manipulation, management, movement, control, display, switching, interchange, transmission, or reception of voice and/or data, and includes software, firmware, and hardware.

In organizational informatics an information system is a system of communication between people. Information systems are systems involved in the gathering, processing, distribution and use of information and as such support human activity systems.

The most common view of an information system is one of Input-Process-Output.