ENS names goes through several stages from being available to being registered and expiring. A life cycle of sorts. This article tries to explain its life cycle in simple terms. As such, the diagrams are simplified.
Temporary auction ends without a buyer the ENS name will become available normally again without a temporary fee attached.
This is when a name is in a registered state and belongs to a wallet address, it will remain in this state until it reaches expiry.
This is when your ENS name expires. After an ENS name has expired, it will still point to your records until it's released.
After an ENS name expires it enters into what's called a Grace period. This is a 90-day window provided as a courtesy where the owner can renew it and keep it at the regular renewal cost.
Keep in mind that the renewal period must be from when the name expired, otherwise the grace period will just be moved up.
For example, if a name expired 60 days ago, and you only extend the registration for 30 days, then the name will still be expired, and the end of the grace period will just be extended for 30 days.
Temporary Premium Auction
After the grace period ends the ENS name will enter into a
Temporary Premium Auction. This is a 21-day period where the ENS name is available for anyone to register with a temporary premium attached.