A Project file holds all the information about your data and how you want to present it.
The majority of your data is read directly from the original source. This allows you to continue using your data in other software packages, with the updates being available in Spatial Integration the next time you open it. Exceptions to this are drill holes and internally managed points (points imported into the Point Manager). Surface elevation grids and images, GIS files and external 3D assets are all read directly from source and processed on-the-fly.
The Project flyout menu allows you to manage your project, including opening projects and creating new projects.
You can also Package your project, which copies the project and data files to a specified directory, where everything can be easily compressed and sent to someone else.