5G is the 5th generation of cellular network technology. The industry association 3GPP defines any system using "5G NR" software as, "5G", a definition that came into general use by late 2018. Others may reserve the term for systems that meet the requirements of the ITU IMT-2020.
5G is the next generation of mobile broadband. This will eventually replace, or at least augment your 4G LTE connection. You can sure get faster download and upload speeds with 5G. Latency (the time it takes devices to communicate with each other's wireless networks) will decrease.
The value of 5G comes from its ability to use a much wider spectrum at higher frequencies. Although, as these frequencies heighten, the ability to penetrate material (like through walls) decreases. Current 4G technology mostly operates on the 700 MHz band of the spectrum.
5G is what carriers are currently building as the next generation after 4G LTE. Whatever comes after 5G will likely be called 6G. So far, 6G exists mostly as a theoretical concept.
5G will improve your network connection dramatically. You will not have to deal with disruptions when sharing videos from crowded places. High-quality videos on your newsfeed will not cause frustration from all the buffering. You will get a faster, more stable and more secure connection. New services could come with this. You will enjoy better performance than ever before.