recognizes apps not installed?

amy

How does  'know' about certain programs that are not installed on my computer?
For example, I tried to run 'svn' the other day and I was told that I didn't have Subversion installed, but I could get by installing a package called 'subversion'.  Same with 'zsh'.

If I don't have the package installed, how does  know where to find it?  I'm guessing it doesn't recognize every executable file in the repository.... right?

Just curious.
Thank you for your time.

It's a new feature in Feisty. I believe it does know every executable file actually. If you look in synaptic, you can right click a package and view the properties, here it will tell you all the files installed by that package, so ubuntu is already aware of which packages provide which commands, it just didn't used to tell you about it.