A Retired Quote will keep all of the orders information in the order, in case you go back afterwards to Reopen it. If you have any scheduled events on that quote, it will not display them on the main calendar.
You will have to go to the Manage Tab in your order and to the Job/Order Settings and you will see the option to Retire.
You will be able to find all of your Retired Quotes by going to your Order List and filtering by Order Status.
You also have the option to Retire your Estimate/Quote by clicking on the box on the top left side and selecting "Retire Estimate".