A page is just an entry. The only thing that make a page special is that you can associate that particular entry with a page uri and template. So basically, when someone browses to the uri of the page that particular entry will be displayed using the template you choose.
If you take a template based approach you setup a template group and template and then the entry displayed is controlled by the segment that contains the url_title for that entry.
Pages are great for static like pages such as about us and contact pages. When you have content that needs to be dynamically displayed based upon url segments then the template base approach is better.