Sockets in Germany: Types C and F, supplied with 230 V at 50 Hz. At 230 V the supply matches what UK and European appliances expect, so no converter is needed.
The same socket system is used in Norway, Latvia, Lithuania and the Netherlands, so one adapter covers all of them. Watch out when moving on: Gibraltar, the United Kingdom and Ireland use a completely different system. In Europe, 31 of 50 recorded destinations use exactly this combination.
Protective earth
Grounded and ungrounded sockets may occur
Mixed supply: Type C without earth, Type F with earth. Which one is in your room only shows on arrival.