The graph to the left is for Eurodollar CD's with 3 month maturities.
Eurodollars are deposits in non-U.S. banks that are made in U.S. dollars. As these deposits are located outside of the United States, they are outside of the Federal reserve's jurisdiction. The result is that Eurodollars are subject to far less regulation than deposits made in the U.S., which can allow for higher returns.
The name "Eurodollar" actually has very little to do with geography. A U.S. dollar deposit made in any country outside of the United States would be considered a Eurodollar deposit.