Somebody else already did a pretty good job explaining it, but in case some additional information helps:

It's sort of like stepping from making couriers go hike on foot in 3G to sending couriers on mountain bikes in 4G. With 4G LTE these couriers received e-bikes and panniers (faster and more stuff to carry). The bikes are not only faster, but can also be used in all sorts of environments (road, gravel, sand, snow, ...), whether it's 4G or 4G LTE.

When we now step up to 5G, we need to distinguish 2 parts: you might here about millimiter wave or highspeed 5G and then there's the 5G sort of representing an evolution of 4G LTE. Think of the latter like this: these bikes and e-bikes that the couriers used were pretty good, but people figured the bikes could be improved, so they slapped on better tires to remove friction and make it easier for the couriers to pedal and support more weight. The person sending the postcard won't really notice much difference, but the courier will notice the difference and be able to service more people trying to send a postcard.

The highspeed/millimiter wave part on the other hand is like handing them motorcycles. Much, much faster and able to carry even more, but don't even try hiking a mountain in a street bike. They'll be really good in some environments, not really useful in others since they just get stuck after a short range.

Now regarding radio and broadcasting:

These happy information rays are sort if like yelling across a room. We can't hear it since our ears aren't made to hear this, just like our eyes can't see infrared or ultraviolet light, but your radio or TV can. Just like yelling, broadcasts can't control who can hear what is being yelled. Everyone in range will be able to hear. You just need to point your ear in the right direction, and you'll be able to pick up what's being said, you might just not know the language it's being said in.

Your mobile phone works on a similar principle. Cell towers are typically divided into sectors. Imagine 3 people standing in a circle with their backs against each other yelling in 3 different directions through speaking trumpets. While the trumpeters might hear something they each say here and there, the trumpets are really good and only yell in the direction they point. In the middle of these 3 stands a coordinator who sees you standing in the direction of trumpeter 2 and tells trumpeter 2 to yell your way. You hear trumpeter 2 telling you about the coordinator and decide to talk to this one instead of another one you can barely hear down the road.

You yell back, but different from the trumpeters, you yell in all directions (in your own language so nobody else can understand), which is why the trumpeter needs much better ears than you do. It also helps that he's sitting higher up so he can focus more on hearing you instead of road traffic or other stuff. Since you're not the only one there, the coordinator will give you all your individual times to talk and will talk to you in turn.

That's how it used to be. 4G LTE added the ability to better divide the time between different listeners, and 5G further added the ability to split sentences between different users (the beginning goes to user A, middle to user B, end to user C). You still get about the same you heard before, maybe a little more if there are fewer people in the room, but more people can now talk at the same time. For the high speed version, the trumpeter puts the trumpet down and tries to hand you a string telephone. You need to get much closer to use it, but it will be clearer and faster once you're there.