Welcome to the Hook Productivity Forum , @Kazza .
There’s a table with details here: Buy Hook – Hook.
In short: Lite mode enables you to use the hooks you’ve added (bidirectionally links shown in Hook window) and
hook:// links (to files and emails) i.e., you won’t lose any of your prior work when Hook switches from trial to Lite mode.
.hook files can be consumed by Hook as well. They can easily be created in any text editor.
It also lets you copy links to emails that you can share with others. That solves an important problem. See our https://hookproductivity.com/help/general/videos/ page for email use cases. And Benefits page: https://hookproductivity.com/benefits .
Hook Lite is a mode, not a separate product.
other details on web page noted above.
Others on the forum may have an opinion re the Lite mode.