There are technically three different license types you can own today.
A perpetual license is one that you own indefinitely. Today, you can’t buy a Perpetual license, you would have had to have purchased it prior to the switch-over to Subscription-only licenses. A Perpetual license gives you access to the product you bought. Forever. You have a serial number for that product, and hopefully the installation files either on a disc, a thumb drive, or you’ve downloaded them to your computer. You will want to hang on to those installation files, as Autodesk never promised to make it easy to own a Perpetual license, just that they wouldn’t take it away.