Hello fellow Lemmings! I hope this is the right place to ask this. I don’t understand how web domains work. Let’s say I want to buy the domain “abcdefghi.net”. I can go to a domain provider like haruba or godaddy and just buy it. but how can they, a private, sell me these domains? I’m not talking about the hosting, but just the domain. where do they register this domain I’m buying? isn’t it possible to register it myself instead of paying these services to do it for me?
Yes, the registrar controls the NS records (and, if your zone is DNSSEC signed, DS records) for your domain in the zone the registry hosts.
[EDIT: I forgot about this part earlier.] The registrar will typically also give you the ability to “register nameservers”, which means specify one or more names within the name space of your domain that you want to act as nameservers and their IP addresses. The registrar will insert A and/or AAAA records into the registry to be used as glue records.
This is probably much further down in the weeds of “how web domains work” than the OP intended.