[jlmorton]

The eventual plan is to build an orbiting space station, the Lunar Gateway. Astronauts will then launch on SLS/Orion, which will perform a Trans Lunar Injection.

However, before that, a Starship will be launched into LEO. There will then be something like 17 (the actual number is not clear, but it is a lot) Starship tankers that will launch to re-fuel the original Starship.

The Starship then does a Trans Lunar Injection. The Orion docks with the Lunar Gateway, Starship docks with the Lunar Gateway, the astronauts transition to Starship, which does a propulsive landing on the moon.

[cubefox]

More precisely, those ~17 ships will fill a propellant depot ship, and once that is done, they can launch the HLS ship, that will then be filled with propellant from the propellant depot.