Types of Information System

The "classic" view of Information systems found  in the 1980s was of a pyramid of systems that reflected the hierarchy of the organization, usually transaction processing systems at the bottom of the pyramid, followed by management information systems, decision support systems, and ending with executive information systems at the top. Although the pyramid model remains useful, since it was first formulated a number of new technologies have been developed and new categories of information systems have emerged, some of which no longer fit easily into the original pyramid model.
Some examples of such systems are:

• data warehouses
• enterprise resource planning
• enterprise systems
• expert systems
• search engines
• geographic information system
• global information system
• office automation.

A computer(-based) information system is essentially an IS using computer technology to carry out some or all of its planned tasks. The basic components of computer-based information systems are:

• Hardware- these are the devices like the monitor, processor, printer and keyboard, all of which work together to accept, process, show data and information.
• Software- are the programs that allow the hardware to process the data.
• Databases- are the gathering of associated files or tables containing related data.
• Networks- are a connecting system that allows diverse computers to distribute resources.
• Procedures- are the commands for combining the components above to process information and produce the preferred output.

The first four components (hardware, software, database, and network) make up what is known as the information technology platform. Information technology workers could then use these components to create information systems that watch over safety measures, risk and the management of data. These actions are known as information technology services.^[19]