Foreign cash includes all foreign banknotes and coins. The cash exchange rate is the rate that the banks calculate for buying and selling these foreign notes and coins. Since there is no official foreign notes and coins exchange in Germany, it results from trading between banks.
It usually refers to banknotes, since foreign coins are traded at a considerable discount, if any, due to the high costs involved. Therefore, all coins should be issued there when travelling abroad.
The foreign exchange rate is about four percent higher than the exchange rate.