Work under European free movement
No visa neededCitizens of European Union countries, Iceland, Norway, Liechtenstein and Switzerland.

Germany visas
Citizens of European Union countries, Iceland, Norway, Liechtenstein and Switzerland.
Nationals from outside the European single market who are employed within it and temporarily work in another single market country for the same employer, subject to conditions.
Travellers without a relevant work right or exemption need appropriate permission to work.
Citizens of European Union countries, Iceland, Norway, Liechtenstein and Switzerland can work in Germany without a visa.
Travellers without a relevant work right or exemption need appropriate permission to work. Citizens of European Union countries, Iceland, Norway, Liechtenstein and Switzerland can work in Germany without a visa.
There are 2 options: Work under European free movement (no visa at all); Van Der Elst temporary work rule (a special permit).
Citizens of European Union countries, Iceland, Norway, Liechtenstein and Switzerland.
Germany does not permit work under the ordinary visa-free short-visit rules. The Van Der Elst rule concerns temporary work for the same employer and has additional conditions.
Yes. Rules depend on the country that issued your passport. Open the Germany visa page and choose your passport for a plain answer.
Yes. Officials can refuse a visa or entry, even after you apply. Give true answers, bring the documents asked for, and keep proof of your onward trip and money.
On Germany's official immigration or foreign ministry website, or at its embassy. Rules change, so check close to your trip.
Often you cannot switch visa type inside the country. Ask the immigration office before you travel if you might need to.
Reviewed by @snuck