Are intellectual property rights transferred when the site is sold?

Question

Law in IT

There is some abstract site with a domain, files, a database and some kind of audience. Some effort has been invested in the development of the site, at least partly something new has been created.
If something specific is not specified when selling a site, what is transferred by default, except for the domain, files and database? What happens to intellectual property, and who, after the sale, has the right to use the developments of this site?
A variant of the situation (not the main question, just an example): what if at the time of the sale a copy of this site already exists and works with a different theme, audience and domain?

Answer 1

Perhaps a similar question:
There is some informational site, it is managed by a manager or a 3rd person.
The site publishes materials, copies, copyright, etc.
All contracts, payments for work - are carried out by the manager.
If the site and domain change the manager (the domain owner quarreled with the person who ruled everything)
and then copyright complaints pour in - what to do?
Although these materials and work were supposedly paid for
(but the domain owner has no supporting information).