I'm not pilot yet, just an enthusiast having some fun in MSFS2020.
What do those colored lines mean in Garmin avionics?
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The various lines you see are used to demark certain aspects of the airspace such as controlled airspace (of differing classes) including terminal manouvering areas, restricted areas, military no-fly zones etc.
You get a slightly clearer picture (if you're used to reading sectional aeronautical charts) by looking at the real thing rather than a display on a simulated GPS.