How it's supposed to work: 5G is faster. 5G has lower latency (doesn't have to reconnect, which all phones do under the hood even when it doesn't seem like it). 5G will have the ability to connect to multiple devices.
How it works now: Available in the U.S. in only a few places and the high frequency makes distance and walls a problem. There were similar problems with 3G and 4G, though, and the more widespread signal towers and purchase of 5G devices will remedy that just like it did with 3G and 4G.
How it'll work in the near future (my prediction): Early versions of 5G devices will be backwards compatible to 4G until most urban areas have 5G.
How it'll work, say, 2 years from now: We may be looking at a point where the signal frequency is too high to never be truly 5G most of the times even in high density areas (thus many cell towers). Too high a frequency = it won't carry a long distance or through walls, even with improved devices. It's analogous to music with high frequency (i.e. electric guitars and cymbals) not carrying through walls or a long distance as low frequency sounds (i.e. bass drum and bass guitar). So we may be looking at the 4G towers never completely going away like 1G and 2G has. It may be that all phones from now on will have to be 4G compatible (unlike, say, your 4G phone not having to be compatible with 2G, but if it's an early 4G phone it might be compatible with 3G).
So all that to say, that the 5G experience of the future will probably be like having a 4G phone in a rural area (my area is sorta rural). I can watch videos on my phone through the cell service with a decent, not great, experience. But there's a big difference using the same phone when I'm in my house using the wi-fi, even if I don't have to manually switch over to wi-fi because my phone does it automatically (after I set it up the first time). I think that's how 5G will be even in urban areas -- where the awesomeness of 5G is intermittent as you walk around the city and every now and then it drops down to 4G in quality. It'd probably be better for the cell carriers to offer a wi-fi service in the high density areas using multiple routers in many businesses (i.e. one on each block) and the wi-fi point named the same thing so you can walk around and always be connected to the wi-fi service, even as you move from router to router (like many businesses and universities already do for their students to walk around campus and be connected to one wi-fi from many points).
Thanks the detailed response. What is your take on the privacy issues l have heard rumblings concerning 5g.
Thanx for 5G info even a cave man can understand