What is the difference between Packages and Plugins?

[SubLemon]

These two terms seem to be used almost interchangeably.

Also how do you setup new plugins? I know how to install packages, but not plugins.

[FichteFoll]

A “plugin” is a Python script that gets loaded by Sublime Text when it’s inside a package at its top level and interface with the Sublime Text API. Essentially, plugins can be part of packages, but packages can consist of many more different types of resources.