MS Windows uses a variety of naming services. DNS is only one of them.
One is NetBIOS Naming Services - Some computers regularly broadcast their name and address and other computers on the same LAN will be able to receive and keep track of these names.
There are a variety of such protocols - Windows PCs and things that coexist with them are irritatingly chatty on a LAN:
Note the "Host Announcement" with "Periodicity" = 12 minutes.