Monocrystalline vs. Polycrystalline Solar Panels - What’s the Difference?

See options of mono and poly solar panels at altE’s website: https://www.altestore.com/store/Solar-Panels/c541/ .
We often get asked by customers what’s the difference between monocrystalline and polycrystalline solar panels. Here’s a surprising comparison of the differences (hint: not as significant as you might think).