Page types allow different pages of your site to have different layouts. For example, the website's homepage could have a landing page layout while an interior page has a standard layout with more focus on the content area.
To add a page type, click on the "Add new type" link and select the type of page you want to add.
Next, you'll be asked to choose the icon that best represents this page type.
This is the icon that will display in the "Pages" tab when choosing the layout for a page.