1 - Page Parts (introductory infos)

go to main page.

the whole system is the web page or web app.
parts: (symbolism of an automaton, humanoid android) these are the changing parts of the underneath software system, called web browser, that browses web pages.

every html page has a structure, like having a title and a content.
every html page has a publishing address to refer to it in links.
every link to a page refers to the page by publishing address and shows a text that can be the title of such linked page. or other contents.

Tipically, especially for more traditional pages, the content is written by a writer that has something to share to the Internet, the graphicians make it readable and pretty, the scripters make the functionality work, like handling some input from user.
In the web apps, instead, as the evolution of such possibilities, tipically the efforts are for the functionalities of the application/software. The content is often provided by users.