What is package selection states of debian packages?

If you try to invoke man page of dpkg, you will see two states about debian packages like me which are Package states and Package selection states.

As far as I understand based on the man page, it seems that the packages are selected by something which is going to install, hold, deinstall or purge each of them.

My question is what is this something? How can we benefit from knowing these selection state?

Solution 1:

1. There are two possible something that set dpkg Package Selection States (what you WANT the package system to look like).

   • You
   • Apt

2. The only benefit of knowing Package Selection States is for troubleshooting when dpkg does not do what you expect. Most users lose nothing by not needing to manually de-conflict dependencies, since apt is designed to happily do it for them.