Is ENS domain free?

Could you please clarify for me, is the ENS domain free to acquire or does it come with a cost? I've been hearing a lot about the ENS system and its potential uses in the crypto world, but I'm still not entirely sure about the financial aspect of it. Is there a one-time fee or are there ongoing costs associated with owning an ENS domain? Could you also explain what benefits come with owning such a domain? I'm really interested in exploring this area further but want to make sure I understand all the costs involved before making a decision. Thank you for your assistance.