WWDC 2023 is coming on June 5 - Here is everything you need to know about the event!
Edge is what ATT calls their non-3G network. 3G is like a DSL line and Edge is like an old 300 baud external modem. GSM is the terminology used to describe ATT's network. There's GSM, CDMA like Verizon and such. It just describes the technology used for their networks.