Difference between a "workflow subscription" and a "workflow association"

Question

Simply put, what is the difference between a "workflow subscription" and a "workflow association".

Here the two terms are used interchangeably.

I have created a workflow named MyWorkflow. When I associated it with my list I named the (what I used to call) association "MyWorkflow_officesupplyList" (...Im using sp online/csom btw)

Answer 1

Well, the story starts even before the WF subscription and association comes into picture. When we use CSOM, it is important to understand that how a workflow is invoked programmatically. There exist a Workflow service Manager which is responsible for getting all workflows for a site. In MSDN words, "This Describes the workflow host configuration states and provides service objects to interact with workflow instances."

Now lets talk about WF Subscription service and WF association.In simple words:

Workflow subscription service: It's one instance manages All workflow associations.

Workflow Association: It simply describes the association of a WF to a particular SharePoint component (e.g association with List or Site)

Needless to say that you will require WF subscription to get association. Please refer the sample code:

var workflowServicesManager = new WorkflowServicesManager(ctx, ctx.Web);            
var workflowSubscriptionService = workflowServicesManager.GetWorkflowSubscriptionService();              
var workflowAssociations = workflowSubscriptionService.EnumerateSubscriptionsByDefinition("guid-of-workflow");
ctx.Load(workflowAssociations);
ctx.ExecuteQuery();