Well, how to explain? :msn_confu
Emulators are small programs that let you play NES, SNES, N64, SEGA, any system on your PC. These games are actually dumps from cartridges and CD rips called ROMs and ISOs. Since ROMs and ISOs are copyrighted material, Emulator-Zone has a no ROMs/ISOs policy that states anyone should not ask and post sites to ROMs/ISOs and we suggest to look in Google or any P2P software like LimeWire or Shareaza, even torrents.
In other words, you can get the emulators here, but you have to find the games by yourself.
Happy hunting