When the crank is turned, the pump sucks the air out of one metal spiral, creating a vacuum. The metal spiral contains a cooling agent that evaporates under low pressures.
Evaporation uses heat that is taken from the metal spiral leaving it cold.
The cooling agent is condensed and becomes a liquid. We say the steam condenses. The pump presses the evaporated cooling agent out into the other spiral. When the air is compressed, a high pressure develops. The steam is said to condense.