Different types of pages

Each page and widget utilizes a certain type.  Each page type will determine what kind of content is output.  For example, a Photo Gallery page type, will allow you to upload a set of images to display in a slideshow format, a Calendar page type will allow you to create a calendar of events that you can navigate around, and a Basic page type will allow you to put any type of content inside without any predetermined formatting.  Look in the Help files for more information on each page type, and test them out to see how it works.