Just for those of you who don't know, my apologies to those who do. Perpetual license means you own it and can use it forever. However if you want updates, patches, etc. you typically have to pay some kind of yearly maintenance fee. The good thing about perpetual licenses is that if you don't want to update to the latest version, the version you have will work forever and you never have to pay another penny.
Subscription licenses however are different. You don't own the software, you are basically renting it. If you stop paying for it, it stops working. Unfortunately most software companies are going the way of subscription licenses.