apadana's questions

At home I sometimes connect to a workstation from my laptop (both are at home). To connect to the server (i.e. the workstation) I use its internal IP in Remmina on my laptop. As the following image shows, Ubuntu on the server gives a Device Name and a Remote Desktop Address for establishing a connection. But I haven't been able to use them at all. Should I set up some sort of DNS first? If I'm not mistaken, on the router device at home I can associate any name with any internal IP address. So why has Ubuntu given these names?

For some packages, in package manager I read that "Canonical provides critical updates for [PACKAGE-NAME] until [DATE]." But what is the formal definition of a "critical update"? For example, if a graphics driver doesn't work properly, would an update solving the issue be a "critical update"? Please cite official documents if possible.

I'm new to Kubuntu. Somewhere I read that Kubuntu only receives updates for those parts/packages which are shared with Ubuntu. Does this mean that there will be no updates for bugs in KDE desktop?

As the following picture shows, I have set the microphone volume to the maximum possible, but the volume recorded is very low despite putting the microphone very close to my mouth and speaking loudly. I do not have this problem with the internal microphone. And this external microphone works properly under Windows.

In Xubuntu 20.04, I can't find a keyboard shortcut for "show desktop". For example, Ctrl+Alt+D does nothing. Of course I can define a new keyboard shortcut. The problem is I don't know what program performs a "show desktop".

As an example, on my system apt-get needs to download 3.5 MB to install the IDE geany, while the download size is 100 MB for snap. This is so big and unacceptable! Even the Windows installer of geany is no more than 15.4 MB in size!

What libraries used by a software are included in its snap file? And what are assumed to be already present on the OS? Does a snap file include all the required libraries? If that is the case, why? I see no reason why more than one copy of each specific version of a library, say GTK, should be present on a system.

Maybe I haven't understood the snap system well enough. Maybe the download size of each snap depends on the snaps already installed. For example, maybe if another application installed by snap uses the same version of GTK, the download size for snap installation of geany would be less than 100 MB.

My laptop has two GPUs: an integrated intel and a Radeon HD 8550M. The latter is from Radeon HD 8000 series. According to the manual of the open source Radeon driver, these series are supported by the driver. I want to use the Radeon GPU, but the integrated GPU is being used by ubuntu and the applications, and I don't know how to activate the Radeon. Thanks.