What is the meaning of 5G status icons on iPhone?

Currently the entire iPhone lineup including the iPhone SE supports 5G wireless connectivity. 5G provides lower latency and faster transfer speeds over 4G or LTE networks. There are several different bands / frequencies which may appear via icons in the iOS status bar when in use:

• 5G - standard 5G network (also known as Verizon "5G Nationwide")
• 5G+ - mmWave 5G (fastest high frequency connection)
• 5G UW - mmWave 5G (Verizon “5G Ultra Wideband”)
• 5G UC - higher frequency 5G with some mmWave (T-Mobile “5G Ultra Capacity”)
• 5G E - actually just 4G with enhancements (AT&T "5G Evolution")