The four tiles are Tracks done (tracks completed at least once out of the total), Steps seen (steps you have viewed out of those available to you), Time left (estimated minutes across tracks you have not finished) and Last trained (date of the last saved progress, with the kitchen name). Quick Start is excluded from these counts because it borrows steps from the other tracks. Training progress is saved per kitchen location: the page says Progress is saved per kitchen – you're on <kitchen>. If you switch the active kitchen in the top selector, you see that kitchen's staff progress, not a lost record. Progress is stored when you move between steps and when you finish a track.