The Apple iPhone 12 supports 5G connectivity, but there are two versions of it with 5G, and the fast mmWave 5G is only available in the USA.
It will be replaced by the iPhone 13, which is later this year. According to reliable Apple analyst Ming-Chi Kuo (via MacRumors), the upcoming iPhone models with the mmWave 5G will be shipped to other countries, most likely Japan, Canada, Australia, and European countries.
Overall, Ming-Chi Kuo claims that load allocation of iPhone 13 mmWave models should grow to 55–60 percent overall.
Outside of the US, Apple’s iPhone 12 is offered with only a sub-6GHz 5G variant, which is a bit faster than LTE. The mmWave 5G is very fast, with speeds ranging from 500 Mbps to 1 Gbps, but with a smaller range, which means cell towers must be mounted more rigidly to offer full coverage. Typically, you’ll see mmWave 5G in crowded urban areas, as well as places like airports and stadiums.
The change may be visible from the outside – but very rarely. Apple’s mmWave 5G model has a visible antenna on the bottom right of the phone, unlike models sold outside the US.
Of course, the main advantage of the mmWave 5G model is the fast uploading and downloading speed, but it will also depend on the availability of your mmWave 5G where you live.