While there is not a traditional user manual for Thunderbird that I'm aware of, there are support articles that may help explain Thunderbird's features. Here is the closest article I could find that explains both versions of the main user interface.

Hmm I was wondering what does it mean in the user interface when it says "Use hardware acceleration when available" It see that for me it is checked should I uncheck it?

Hmm I was wondering what does it mean in the user interface when it says "Use hardware acceleration when available" It see that for me it is checked should I uncheck it?

It is a rather esoteric setting and really has no correct settings. The correct value depends a lot of the video driver installed on the system and the capability of the video card installed on that device. Generally you turn it off if things get blurry or render in an odd manner but otherwise on makes video and some other functions happen faster. I lost the argument for it to be defaulted to off some 10 years ago. The argument is they (firefox) don't test the off default only the on one and as it is a Firefox feature Thunderbird developers really do nothing except set the initial default value.

Thanks for the explanation Matt, this is helpful, however, I'm not sure I'll be able to remember this in the long term. I can see myself having this same question again 12 months from now. Is there any way that I might be able to configure a hyperlink in the settings so that in the future when I click on "Use hardware acceleration when available" it will take me to this specific forum discussion page? Like, is there perhaps a plugin someone has made for this? Or are plugins not allowed to make changes to the settings page?

Thanks for the explanation Matt, this is helpful, however, I'm not sure I'll be able to remember this in the long term. I can see myself having this same question again 12 months from now. Is there any way that I might be able to configure a hyperlink in the settings so that in the future when I click on "Use hardware acceleration when available" it will take me to this specific forum discussion page? Like, is there perhaps a plugin someone has made for this? Or are plugins not allowed to make changes to the settings page?

No.

But you always have access to your questions here. https://support.mozilla.org/en-US/user/antifascist/\

Perhaps remember how to find your own previous questions