So, let's say we want to search through the repository, and we're looking for
something specific. What we'll do is type "apt-cache search bluefish*" and then the
program we want followed by a asterisk, and this means it's going to find anything that
has the word bluefish in it. I can type "apt-cache search gimp" and it's returning a
lot of stuff. Now we can't find it in here, gimp. Let's say we want to see if we've got
something installed. We're going to use apt-cache again, we're gonna type "policy"
as the action, and then gimp. We see that this is the version we have
installed, 2.8.14, and the official repositories contain this version,
2.8.14. Which means you can see here we've installed gimp through the
repositories. Now additionally you can go to gimp's website, I believe it's gimp.org
and you could download an installer file from there. So, if you're on an older
version of Ubuntu that doesn't have version 2.8 of GIMP in the repositories,
you can actually manually install that package file, and we're gonna go over that
in a moment. So, if I type "apt-cache policy bluefish" which I just
removed, we will see that we have (none) installed, but we can install version
2.2 from the official repositories.