What determines which column an event will appear in?

Columns differ by the role of the user: 

• For Submitters/Organizers there are 4 columns; Require Action, Pre-Event, Post Event, and Completed. The event will always appear in either Pre-Event, Post Event or Completed based on the state of the event. Along with appearing in one of these columns, if the Submitter has action(s) to complete, the event will also appear in the Requires Action column. 
• For Approvers there are 3 columns; Pending Approvals, Approvals Claimed By Me, and Completed. All events appear first in the Pending Approvals column. They then move to the Approvals Claimed By Me column once the claims the event, then finally move to the Completed column after the action for the event has been submitted.  
• For Contract Coordinator there are 3 columns; Contract Pending, Contract Claimed By Me, Contract Executed.  All contracts appear first in the Contract Pending column. They then move to Contract Claimed By Me once the Contract Coordinator claims the contract. Finally the contract moves to Contract Executed after the contract has been submitted.
• For Payment Reviewer there are 3 columns; Pending, Payments Claimed By Me, and Completed. All payments first appear in Pending then move to Payment Claimed By Me after the Payment Reviewer claims the payment, then finally to Completed after the payment review is completed.