The Status Key on the left hand side of each project informs you which tabs have been completed, and whether a tab needs action, needs further attention, or is completed. Wherever you see a purple circle with a white question mark, you can hover your mouse over it and further help and information will appear about that specific section.
User Authority Key
The User Authority Key on the left hand side of each project tells you who is resposible for completing that section. You can hover over the symbols to get more information about that role.