James Webb Space Telescope

The mass that the JWST orbits at L2 is the Sun and the Earth. It's actually considered an unstable lagrange point. The JWST is in the L2 because the Earth keeps it in the shadow of the Sun, less interference.

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I get the existence of the L points and why it's ideal to park stuff there, but why the orange circle indicating an orbit around L2 WHILE orbiting the sun? The perpendicular orbit around L2 while it tracks the earth orbit around the sun? Why not just hang out out there at L2?