"An information system can be defined technically as a set of interrelated components that collect (or retrieve), process, store, and distribute information to support decision making and control in a organization. In addition to support decision marking, coordination, control, information systems may also help managers and workers analyze problems" according to Laudon and Laudon.
Types of Information Systems:
- Transaction Processing Systems (TPS) - System that performs or records daily routine transactions such as sales order entry, payroll, employee record keeping, and shipping.
- Management Information Systems (MIS) - It designates a specific category of information to middle management. It is to monitor and control the business and predict future performance.
- Decision-Support Systems (DSS) - Support nonroutine decision making for middle management. Example of a nonroutine decision: What would be the impact on production schedules if we were to double sales in the month of December?
- Executive Support Systems (ESS) - Help Senior management to address strategic issues and long-term trends, both in the firm and in the external environment. Examples: What will employment levels be in five years? What products should we be making in five years?
I guess you could look at Google and Wikipedia as an information system from a consumer's point of view. Depending on the course you are taking...the instructor is probably looking for one the types of above. Good luck
Management Information Systems, Managing the Digital Firm by Kenneth C. Laudon and Jane P. Laudon. 11th edition. Page 16 and pages 42-50