Pages have different types and are used in various places in the live view. They are used to:
Go to the Content editor by selecting Content in the top left corner, and go to Pages:

The page type is selected when a page is created.
The recommended way to create informative text and images. The content is edited by using a rich text editor, which allows different fonts, colors, images and more.
Images are added by Drag and drop:

Forms are used to collect input from the user (such as name, email, etc.) before completing a configuration, or the dimensions of a room.

Forms contains Fields. In the image above, there's five fields (name, email, tel, notes, checkbox).
Selecting the correct field type is important to enable auto complete.

Legacy - the WYSIWYG type is better suited for displaying text and images
Displays the information in a list format. Add a Field for every entry.