Is Blender a one-time purchase?

I'm curious to know, regarding the software Blender, is it a one-time purchase or does it require recurring payments? I've been hearing great things about its capabilities for 3D modeling and animation, but I want to make sure I understand the financial commitment involved before diving in. Can you clarify if Blender is a perpetual license that I can use indefinitely after the initial purchase, or if there are ongoing fees associated with using the software?