Another very often used construction is the one with um zu + infinitive. The idea is that one action describes the means to reach a result or for another action. The English grammar does know no difference in this. The translation is simply with the preposition to.
Er ging in die Bäckerei,
um Brot zu kaufen.
= He went to the bakery's to buy some bread.
Um deutlich zu machen, was ich will, erkläre ich es noch einmal.
= To make clear what I want, I explain it once more.
Er studierte Medizin, um den Leuten zu helfen.
= He studied medicine to help people.
Er lebt, um zu arbeiten.
= He lives to work.
Since in English it is always the preposition to it is not easy to know whether the German construction is with zu or with um zu . The difference is the aim or the means (=> um zu). However, everyone will understand you if you mix them up. So, just don't worry about this subtlety too much.