Visitors to Germany from certain countries require a visa. All EU Member States and a number of other countries are exempt from this requirement. You can find out whether or not you need a visa by checking the website of the Auswärtiges Amt (Federal Foreign Office).
If you need a visa, you must apply for one at a German embassy or consulate before entering the country. Make sure you contact the German embassy or consulate in your home country in good time to clarify any outstanding issues and to find out how long the process is likely to take. The internet addresses of all German embassies and consulates can be found on the Federal Foreign Office’s website.
After arriving in Germany, most foreigners will need to apply for a residence permit (Aufenthaltserlaubnis) if they intend to stay for longer than 90 days. It is essential that you state your actual purpose of stay when applying for your visa. Often it is not possible to change your purpose of stay after having entered the country. Never enter Germany on a tourist visa! Tourist visas are only valid for three months and cannot be converted into residence permits.
Even if you may enter Germany without a visa, you may still have to apply for a residence permit if you intend to remain in Germany for longer than 90 days! EU citizens are exempt from this requirement. They, like German citizens, simply have to register at their new place of residence.