About

An html page is a logical representation of a HTML document.

Relation between HTML document and page

Generally, one HTML document is one page but with the advent of javascript, you can create pages on the fly (modify the HTML DOM document) and the definition may change and get blurry.

Id

The id of a web page is the URI shown in the address bar of a browser.

The page is served by a web server in the body of an HTTP request created and rendered by the a client that is mostly a browser.

Type