Workflow
Workflows are a simple way to extend the logical operations of your Force.com applications. A workflow is an action which is triggered by inserting or changing a data record. A workflow can trigger a task, email alert, update a data field or send a message.
Workflow rules specify the criteria which determine if a workflow is triggered. A workflow can be triggered immediately, or set to operate at a subsequent interval after the triggering event. These outbound messages are one of the ways you can send information from your Force.com environment to external data stores and applications.
A specialized type of workflow called an 'approval' can route information to a series of people, each of whom can approve the information, sending it on to the next recipient, or decline the approval.
Articles and Presentations
Building Smarter Apps Using Formulas and Workflow: a great webinar showing how to use formulas to improve applications
Official Documentation
- Workflow: Automating the Process PDF
- Getting Started with Approval Processes PDF
- Email Approval Response FAQ PDF
- Useful Workflow Rules PDF Over a dozen examples of how to use workflow in a Force.com app.
- Useful Approval Processes PDF Four detailed examples of how to use approval processes in a Force.com app.