H+ stands for HSDPA+ (High speed Downlink Packet Access), which have much higher speeds than normal 3G network.
It is an upgraded version 3G network but it is not 4G . so if you have H+ then your internet or network is more better than 3G and one thing is that H+ is used only for data downloading.
Based on your network, h+ can handle speeds up to 42Mbps. 3G can only 384kbps.