Citizens of EU/EEA Countries

If you come from an EU member state, Norway, Iceland or Liechtenstein, then you do not need a residence permit. You can start a job and do not need an EU work permit.

You can provide evidence of your right of residence with your passport and certificate of registration.

Citizens of Switzerland

Citizens of Switzerland must apply for a residence permit at the relevant Foreigners' Registration Office within three months of their arrival in Germany.
Further information (only in german):

Citizens of Third Countries

If you are not a citizen of the European Union (EU) or Iceland, Norway or Liechtenstein, you require a so-called "residence permit" for a stay in Germany.
The following residence permits are available:
The residence permit also governs whether you can engage in employment in Germany and what employment you can pursue.
It sounds complicated but the the team at the Welcome Centre will gladly help you to apply for the residence permit that is right for you.