Based on man apt-get for autoremove we got
autoremove is used to remove packages that were automatically installed to satisfy dependencies for some package and that are no more needed.
Can any one tell me what is satisfy dependencies meaning ? I see this command widly used also in somewhere which we do not instsall any thing. Ok what is autoremove realy is and why it used
A dependency is a package required by another package to complete its own functionality. There are two popular packaging mechanisms:
Both these mechanisms use the concept of dependencies. Ubuntu uses debian packaging.
If A and B are two packages and A is a dependency for B, satisfying dependency means installing the version of package A as required by B. So, if you just remove B, A will still be there on your system. If you do sudo apt-get autoremove and no other package requires A, then A will be removed. However, note that if you remove A, B will be automatically removed since B depended on A.
If the package pkg1 depends on the package pkg2 and you install pkg1 then the package manager will automatically install pkg2 to satisfy this dependency.
If you later remove pkg1 again, the package manager will not automatically remove pkg2.
apt-get autoremove will remove packages like pkg2 that got installed not because you asked for it but because you installed and later removed another package that depends on them.
