Fifth generation cellular networks have begun to roll out in 2019, but will really only begin to be majorly relevant starting in 2020 and beyond.
This represents a 10x - 50x increase in network throughput and capacity compared to the fastest 4G/LTE networks.
5G will enable a whole range of next generation applications ranging from autonomous connected vehicles to augmented reality to ultra-HD video streaming.
5G will take advantage of many chunks of spectrum ranging from long range UHF frequencies up through short range extremely high millimeter wave frequencies.
When broadcast over long range frequencies 5G may only have a modest speed improvement over 4G/LTE, but in core urban and suburban areas that are frequently overloaded the extra capacity that 5G brings to cellular should allow for dramatic improvements.