Components of workflow architecture:
One can create workflows using Visual Studio2010 workflow designer. Every single workflow is compiled into its own dll. One needs to create a Workflow definition (XML based) to use it in a farm. The xml consists of the following information:

Name, GUID and description of the workflow
Location of any custom forms being used by this workflow
Correct class within the assembly that is to be called.

Each server farm contains an association table for workflow, which links various workflows to the content type, list or document it applies to. It also includes information regarding how the workflow is initiated i.e.by users or automatically along with the tasks associated with that workflow.   _{Your Comment}