long ago, when somebody fired by his boss, we can say, 他可以卷铺盖走人了。卷铺盖means fold the quilts. when cooking squid(炒鱿鱼),the heated squid become curly which looks like quilts that are folded.
辞职和离职是自己离开。Employees leave the company voluntarily.
辞退和炒鱿鱼means a boss discharge somebody. but 辞退is formal ,炒鱿鱼is not polite.
if you want to fire somebody, you can say, I don't think he is suitable for keeping working in our company.我认为他不适合继续在我们公司工作。