The Workflow Management Coalition (
http://www.wfmc.org/) defines 'workflow' as:
The automation of a business process, in whole or part, during which documents, information or tasks are passed from one participant to another for action, according to a set of procedural rules.
There can be two basic types of workflow:
Activity based - means that the processes, the workflows, are made of activities to be completed in order to get something done.
Entity based - means that the focus is set on a given document and the states it has to go through in order to be completed.