set of web pages

collection of web pages that share a common purpose and that are created by the same author, group or organization

Examples include:

a publication which is split across multiple web pages, where each page contains one chapter or other significant section of the work. The publication is logically a single contiguous unit, and contains navigation features that enable access to the full set of pages.
an e-commerce website shows products in a set of web pages that all share the same navigation and identification. However, when progressing to the checkout process, the template changes; the navigation and other elements are removed, so the pages in that process are functionally and visually different. The checkout pages are not part of the set of product pages.
a blog on a sub-domain (e.g. blog.example.com) which has a different navigation and is authored by a distinct set of people from the pages on the primary domain (example.com).

Different language versions would be considered different sets of web pages.