ICANN: "Remember, paying to register a domain name is not the same as "buying" it outright or permanently. You do now "own" a domain name. What you are doing is more like leasing the domain name from the registry operator that the domain name is associated with. Registration periods can vary depending on the registry operator. You cannot buy a domain name forever. However, you can continually renew its registration (before the registration period expires) to maintain control over it. While the term "buying a domain name" is also commonly used in relation to purchasing an existing domain name registered to someone else, the purchaser is not buying the domain name, but just acquiring the rights to register it to themselves and continue to manage and re-register it in the future."
[1] https://www.icann.org/resources/pages/faqs-84-2012-02-25-en#...