A hub is both a slang term & real term with publications on the internet within specific search engines. The slang term used here at HubPages is it is an article published through the self publishing site HubPages.
HubPages is a domain name, is an authority & is a 'Hub'. The hubber or member has a subdomain or is the second leg of the flow chart. First is the domain then the subdomain and then the articles and etc.
There are 'Hubs and Authorities' receiving HITS or Hyperlink-Induced Topic Search. Or, you search at the search engine a link is provided and you arrive at a page to view. A HITS occurs with a view. The slang term is a 'hit'.
The entity HubPages is a hub. A hub directs toward other entities with information. The subdomain profile pages for the hubber is a page. Also, the hubbers profile page is a hub. The hubber profile & articles are a page to HubPages the entity.
The articles are a page to the Hubber or subdomain. And, the article is a hub with links going elsewhere serving the user when they are searching. A web of links to pages forms from Hubs. Everytime a user acts on the opportunity of a hyperlink leading elsewhere a HITS occurs.
The founders of Hubpages apparently were very wise and quick to categorically act on the opportunity of the domain name identity "HubPages". It cannot be copied as long as they have ownership and rights to its usage.
The same occurs for the hubber with a subdomain under the domain - HubPages as the acting authority. A hubber's profile is, again, a page & too serves as a 'Hub' with Authorities. So, a Hubber profile page is a 'Hub', is an Authority, and has Pages (articles known in the slang usage as a hub) receiving HITS.
Thus, loosely . . .
HubPages (Domain) is a Hub & a Page for the internet search engine (the result of following a link known as a HITS)
The Hubber's Profile Page (Subdomain) is a page for HubPages and is a Hub for the Hubber
The Hubber's article is page for the Hubber's Profile (a Hub) and it is a Hub when links are of avail leading elsewhere. Plus, both are still a page for HubPages, which is a Hub.
The links lead to a page, which may / may not be a hub from the definition of the language of internet. That is dependent if it serves as a hub with hyperlinks leading elsewhere.
Every page falls under an authority & a hub. Those authorities can be & many times are regulated by Terms of Service (TOS) agreements. As a hubber privilege of linking is offered to a page or hub (article).