A project is an individual file that you create within Dorico. It can contain multiple separate pieces of music of any duration, written for any combination of instruments, and use as many layouts as required.
For example, you can create a single project that contains all the preludes and fugues in Bach’s “The Well-Tempered Clavier” as separate flows. You could then have one layout that contains only the flows for Book 1 and another layout that contains the flows for Book 2.
In addition to the notated music, projects save other relevant information, such as the playback template applied, its page templates, and settings in options dialogs.
Dorico projects are saved as .dorico files.