When you start working in Pro Tools | First, you create a project. A project is the document that Pro Tools | First creates when you choose File > Create New. Pro Tools | First can open only one project file at a time. A project is a timeline-based map of all elements associated with your song, including audio and MIDI, and all of your edit and mix information. A Pro Tools | First project does not contain any audio files itself. Instead, it references audio files cached on your computer (and that are stored online in your Avid Cloud Storage Account). Pro Tools | First can only have one project open at a time.