To try and make it clear and hope it clears it up.
2G (2nd generation network) (GSM)
G = GPRS (General Packet Radio Service) Average speeds of 32 to 48 kbs (kilobits per second)
E = Edge (This is a upgrade of GPRS or a enhancement) Enhanced Data rates for GSM Evolution. This speed can be upto 384kbs
3G (3rd generation network)(UMTS)was first arround 384 kbs as well,
However 3g was then upgraded to HSDPA (High-Speed Downlink Packet Access)
and currenlty this can be as high as 7.2mbs (depending on network, location, ussage, where you are, times and so on
Need Help, Just ask. We are one big Family here in the o2 Forum.
Use iPhone XS Max dual sim, SE, Honor 10, IPad Pro 11, Apple Watch 4 LTE, 100+ Mpbs Barrier and a Record Player.