Xilinx ISE (Integrated Software Environment) is a package that contains the suite of programs needed for the entire FPGA development flow. Includes design entry, synthesis, P&R, device programming. Also simulation via modelsim, as an option.
Xilinx EDK (Embedded Development Kit) includes tools for embedded processors supported by Xilinx. They have powerpc cores on some of their high end virtex chips, and the microblaze/picoblase softcore.
Thank you very much. You answer is very clear. So if I don't want to develop embedded processor applications, ISE is enough for using and I don't need to use EDK.