Indicates that an action ought to be done or is desirable/expected (used in patterns like 'should do' / 'ought not to do').
やるべきことを先に終わらせよう。
Let's finish what we should do first.
もっと真剣に考えるべきだ。
You should think about it more seriously.
他人の意見も聞くべきではないか。
Shouldn't we also listen to other people's opinions?