What Exactly Do All These Features Do?

what's up with all these hi-tech features here
http://www.cellphonestalk.com/cellphonenew...-cellphone.html

HSDPA (High Speed Downlink Packet Access), UMTS (Universal Mobile Telecommunications System) and EDGE (Enhanced Data for Global Evolution) wireless network capabilities.

what exactly do all these features do? provide super-high internet surfing speeds? nice phone reception? or more than that?