The project file is usually a single zipped file with the extension FPZip. The zipped file contains three separate data files.
The Project Settings File (*.FPProj) is an XML file containing the project settings and Data Manager definitions.
The Unlimited Database File (*.db) is a SQLite database file that contains information pertaining to the current forecast period and all previously archived forecasts.
The Project Snapshot File (*.fcb) is a binary file that saves the forecast components that are currently in memory (e.g., the forecasts, summary statistics, etc.) so that the session can be restored without having to read in the data, recalculate the forecasts, etc. This allows you to return to your session where you left off and to share the session with others.