A Project is used in GreenDesk for tracking progress towards achieving credit points for an application for a green certification scheme or industry standard, for collating all necessary compliance documentation, and for preparing a final application for submission to the certification scheme authority.
Each certification scheme has a different kind of project, usually pre-created for you for use in a specific version of GreenDesk. Many certification schemes have different variations on projects for different project phases/stages such as 'design', 'as-built', and 'operational'. GreenDesk usually pre-loads with demonstration projects for exactly one of each of these phases, and when you create your own projects you may choose what kind or phase.
Therefore, a typical "real-world project" will have more than one GreenDesk project, with at least one for each of the phases/stages defined in the certification scheme.
Each project is also related to the Credits elements for its certification scheme.
When a project for a particular certification scheme loads it offers additional menus for that certification scheme, including access to specific Categories, and a final calculation over all credits.
Most view pages and rich interactive worksheet pages will tell you which project you are currently working with, or - if you have not chosen a current project yet - will remind you to please choose one.