Saving web pages

I see that we can save a webpage with the extension as many different formats, including bookmark, html and web archive.

What is the difference between the 3. I guess a bookmark will only work for as long as the page exists with that URL.

Thanks in advance

See a lot of very helpful information on page 24 of the user handbook, which includes the following:

Bookmark: Captures only the address (URL, uniform resource locator) of the page.
HTML page: Saves the source code of the page to the database, but images are downloaded from the web each time the page is displayed in the database.
Web archive: Saves both the HTML code and all resources, like images, necessary to display the page.
Rich/Plain text: Grabs selected text/ images and hyperlinks, but avoids saving unwanted areas of the page to the database. A plain text capture will not include formatting, images or links.
PDF: “Freezes” the web page, just like printing to paper. PDFs from web pages can be paginated or non-paginated.