In this page you will be able to approve and create invoices on the projects in which you have the status as "project owner", represented with a blue star on the project's main page. (to read more about how to set up a project please read this article)
The filter on the right lets you set a more defined view of the projects in which you are project owner.
If your company has the settings enabled for invoicing of several projects at the same time, you will be able to create drafts from several projects with a few clicks. This setting can be found under Setup > Settings > General: