Samsung redesigned its double-barrel wireless charger -- useful if you want to charge two phones, or a phone and a watch. You can also transfer a charge from the wireless pad to the phone and use the back of that to charge up another accessory (it'll just take longer).
The back is where you can tell the difference. The S10E has those two rear cameras, while the S10 and S10 Plus have three each. The S10 5G has four cameras on the back, one of them a 3D sensor to help with depth shots and AR.