The Research Tree.
Progression runs on three tracks. Tiers are the eras of the climb: Cosmic Beginnings, Surface Expansion, Factory Founder, Orbital Reach, Particle Physics, Atmospheric Command, Planetary Engineering and Stellar Ascension. Milestones open each tier once every node in the tier before it is researched, and research nodes are the individual unlocks inside each tier. Click any node below and the whole prerequisite chain lights up, so you can see exactly what it takes to reach the Dyson swarm from where you stand.