A Web Page, in UPK terms, is a single file that can contain text or images. In this respect, Web Pages are very limited. You can perform rudimentary font formatting, provide lists, and insert images, but that's about it. You cannot insert tables, or use any HTML tags as you would be able to with real web pages (which you can only use via a Package). However, they are very flexible, and can be utilized in a number of ways.
For readers familiar with OnDemand version 8.7 and earlier, Web Pages are the new, improved text Infoblocks. Other types of Infoblocks have been replaced by Packages, which are covered separately, below.
The most common use of Web Pages is ...