About SWR (VSWR)
The standing wave ratio is one of the antenna system parameters and is often misunderstood by HAMs. The ARRL provides many publications about Antennas, SWR as well as this article available as a PDF document “Understanding SWR by Example”
For a better visual grasp and more comprehensive information about SWR, see this in-depth presentation by Dave Casler, KE0OG, featured here from his excellent YouTube channel.