The one thing you're guaranteed to find in every active instance of Salesforce.com is interaction. It is a given that your users will add,edit,and/or remove data from your org on a regular basis. Consider these updates to Salesforce.com as the first step in your automation efforts. The second step is making Salesforce.com do what you want based on that initial user interaction with no further manual activity from users. What Salesforce.com refers to as a "workflow rule" is an extremely powerful way to take one of these regular every day interactions and allow it to drive your business forward without spending the time or money to have additional people or systems make the change happen. At the simplest level, I can describe workflow rules as operating as explained below:
1. Workflow rules look for a particular state of specific data (your criteria).
2. The workflow rules "fire" (i.e., become active) if the state of the data satisfies the configured criteria.
3. The workflow rules trigger designated, automated actions to occur.
The "base object"(my term, not Salesforce.com's) is the object on which the initial, manual (non automated) data change will be performed. For example, assume you have a custom object called Property that has a Master-Detail relationship to the Account object. If you wanted to make a change to a Property record to drive an automated, system, you would identify the Property object as your base object. That may seem obvious, but it is important to note that the object that is automatically updated through a workflow rule may differ from the base object. In Figure I have identified the object being updated as the "action" object. In other words, a change to Object 1 may trigger an automated update to Object 2; this is called cross-object workflow
The base object refers to the object where the initial activity occurs, not necessarily where the update takes place. On the left side of the diagram, Object 1 has a Master-Detail relationship with Object 2 that allows configuring a workflow rule to update an object different than the base object.
As you can see, you have a significant amount of flexibility to build efficiency and productivity into your system using "Clicks, not code." With the right preparation, some creativity, and a little hard work, you can ease the burden on your employees and make your system data much more meaningful. Make sure to plan out your workflow rules carefully and test them extensively and you'll be able to move your business forward with a notable degree of efficiency.
Image reference : www.slideshare.net/Autotask/workflow-rules-garethbrown