Calibre and Calibre Web, Oh My

I’ve tried googling this and asking AI and the answers I’ve gotten are all contradictory, so I’m asking here in hopes that a knowledgeable person can help me understand. What is the difference/relationship between the Calibre and Calibre Web apps on the TrueNAS App Catalog? Do I want to install one or both of them? I’ve never used Calibre before but my mental model is that it is sorta like Plex but for ebooks is that correct?

Personally I would suggest calibre-web

I have both installed and even Calibre looks exactly like the version on your PC, it works not so well and have lots of bugs.

Calibre-web from another side is very web-ish and is just easier to use on web-browser

The only thing you have to be aware, with calibre-web you can read in the browser only epub books, so technically, you have to convert them all in ebook.

Other formats, you just can download but not open directly in web-browser, the way you do those epubs

I used this for a while for my partner who read a lot. You can install Calibre or install both and have a nice look to the admin. It depends on what you want from it but I personally just removed them in the end and just used a folder that the client uses and maintains - sorry can’t recall the name as even that has gone now. But for my need Calibre was worth the effort, might be different if you have a lot of people wanting it, I had one.