| Event Receivers | Workflows |
| Cannot be initiated manually | Can be initiated either manually or automatically |
| Event receivers can be either Synchronous or Asynchronous | Workflows are always asynchronous, i.e. workflows get executed after the action/operation |
| User interaction is not possible in event receivers | You can use various forms like initiation form, association form for user interaction. |
| You can cancel running synchronous(before committing to Content Database) event receiver | You cannot cancel workflow action as the change is already made in Content Database(workflow = always asynchronous) |
| Can be created only in Visual Studio | Can be created using Visual Studio, Visio or SharePoint Designer |
| Event receivers execute on WFE, so if WFE reboots, event receiver may end abruptly without complete execution. | Workflows are robust, can continue after WFE reboots. |
| Event receivers run for very short period of time | Workflows can run for days, weeks, months or even for years!! |