Over time, especially with Ubuntu and it’s 6 month release cycle, a system can contain a number of packages that are no longer needed but still present on the system in some way. I have a number of techniques I use to locate these packages and remove them and I thought I would share them.

I often find myself asking the same questions about package dependencies. It can sometimes be confusing to remember which command answers which question due to the similarity of the commands. These are the common questions: