When we teach the Technician License Class, we provide a simple explanation of Standing Wave Ratio (SWR) that emphasizes the concept of impedance matching. An SWR of 1:1 is a perfect match; anything higher is less than perfect.
SWR is an important amateur radio concept, one that is not that easy to explain so I am always on the lookout for training materials. HamRadioNow just republished this video of excellent standing wave demonstration by Bill Hays, AE4QL. Bill actually goes well beyond just standing waves and shows some antenna and transmission line theory as well.
If you just want to learn about standing waves and basic antenna radiation, view the first 35 minutes. After that, it starts to get a little deep.
Grab a cup of your favorite beverage, settle in and get ready to learn from this video.
73, Bob K0NR