ProjectsImagix 4D uses the term project for the repository of all the information it retains about the specific portion of software you're exploring. As you import data for viewing, Imagix 4D extracts information from the data source, and loads it for viewing. Most of this information is permanently stored in your current project.
All of the permanent information about a project is stored in a directory structure in your file system. As such, projects are a shared resource. Normal file read and write permissions apply to the project directories and files. Through your standard permission mechanisms, you're able to control who can access and who can update projects. Top level directories for Imagix 4D projects use a .4D suffix so that you can identify them as such.
As your use of Imagix 4D increases, you'll find that managing what data exists in which projects is an important part of maximizing your benefit from using the tool. More data enables you to analyze a wider range of information without having to leave the project. However, it also causes you to filter through more information to find the particular information you're interested in. Larger databases also cause somewhat slower response times.