The electricity in Germany is 220 volts AC, 50 cycles, 2 phases. The wall sockets are 2-pin/prong. Large electrical appliances over 3 KW require 380 volts, 3 phase. To use appliances from elsewhere, you will need to get transformers. They can be found at large appliance stores and electrical shops. Using plug adapters, you can use non-European lamps with German bulbs in the wall sockets. Note also that the standard bulbs in Germany use a screw rather than a bayonet fitting. If you are coming from the UK and have lamps using bayonet bulbs, bring spare bulbs. Dual voltage appliances can be plugged directly into the socket provided that you have the proper plug or adapter.
Water is soft in Bonn: less washing powder is needed.