The metadata information of Pages is rather self-explanatory. This meta information can be found in all kinds of document files, including the Microsoft Word family (DOC, DOCX, DOT, DOTX, DOCM), HTML files, PDF documents as well as other Microsoft formats such as presentations (PPT, PPTX) and spreadsheets (XLS, XLSX).
Some images can contain a value for Pages as well. What they all have in common is that these image formats can contain multiple images resp. layers that can be considered Pages. This includes the Adobe PostScript format PS and other PostScript image files like EPS.
Per definition, pages are single sheets of paper, in a book or magazine or the like, with or without content on either or both sides. This can be translated into digital media as well. In documents, this is visually represented as “literal” pages as well. It can also refer to the amount of content that is displayed on a computer screen at one time as well.
In a file, the Pages metadata always contains a numeral value. It indicates the number of Pages in a document, sometimes also e-book. Sometimes, it can also be represented as “n_pages” or “num_pages” which stands for number of Pages.