I've seen in various places some frameworks being described as easy to great ways to create single-page websites; such as Bootstrap and Angular. My question is why only single-page? Isn't it just as simple to use them to create multi-page websites?
By Single Page Application, one usually refers to a site which after its initial load, the site loads all resources required by using AJAX-calls which prevents the users browser from having to do an "hard" reload of everything that is displayed. In certain solutions, it is common to find sites where the entire site would be reloaded even though only a small portion of the data displayed was actually changed.
What angular and other Single Page Application frameworks does, is that it gives you the scaffolding to easily build sites made from multiple .HTML-files (as well as other resources) which are loaded asynchrounously as needed.
To answer your question, it very likely that you would end up with more than ONE actual "page" (html-file) in any SPA-framework driven website. The Single Page Application-terminology mainly just refers to the fact that you are never performing any "hard" reloads from that point on, you are just appending or removing "views" from that initially loaded .html-page using javascript.