Good info from @Mr_McBride and @astronautsupplier.
Here is the direct link to the Ubuntu documentation on updating packages:
Working with apt-get
Working with repositories
One additional piece of info that sometimes gets skipped over is that the version of an installed application is controlled by the repository.
You see and hear the news about Inkscape version 1.1 being available. You want to use that version so you enter:
sudo apt-get update
sudo apt-get install inkscape
Then you get a response that says Inkscape version 0.92.5 “Your application is up to date” or something similar. Wait! It’s not up to date. Where’s version 1.1? This lag in application versioning occurs because your system is polling Inkscape through the standard repository and is not polling Inkscape directly.
In order to polling Inkscape directly, I have to add the Inkscape PPA (Personal Package Archive) to my list of repositories that I want to poll. Fortunately, the Inkscape website tells me how to do this:
sudo add-apt-repository ppa:inkscape.dev/stable-1.1
sudo apt-get update
sudo apt install inkscape
BOOM! I now have Inkscape 1.1.
I can see that this custom PPA has been added by looking at the contents of etc/apt/sources.list.d
ls -l /etc/apt/sources.list.d/ink*
-rw-r--r-- 1 root root 148 Aug 5 14:45 /etc/apt/sources.list.d/inkscape_dev-ubuntu-stable-1_1-focal.list
All of this versioning can be seen by looking at the results of the following command:
sudo apt-cache policy inkscape
which will now report:
*** 1:1.1+202106031931+af4d65493e~ubuntu20.04.1 500
500 http://ppa.launchpad.net/inkscape.dev/stable-1.1/ubuntu focal/main amd64 Packages
500 http://us.archive.ubuntu.com/ubuntu focal-updates/universe amd64 Packages
500 http://us.archive.ubuntu.com/ubuntu focal/universe amd64 Packages
You will almost never have to do this – but I’m letting you know because there might be that one package that you have to have as a most recent release.