Cancellation before the departure date, usually results in a "change fee" to the original ticket. It is non-refundable but it is cancel-able... you just won't get your money back, and you'll have a credit with that airline; minus the change fee (usually around $150 these days). So - you're not really CANCELING the ticket... you're just rescheduling it. You usually have 1 year from date of travel to re-schedule A trip with them, for your credit to be valid.
A FULL FARE ticket or "refundable ticket" usually 2-3 times more expensive means you can make changes to the ticket such as travel date, and it's unrestricted, meaning no change fees.
However... DO cancel the ticket, and don't just no-show. A No-show entirely voids any chance of credit with the airline.