1G allowed analog voice calls with the first cell phones. 2G made things digital and introduced text messaging. 3G brought phones online. 4G made smart phone internet fast and reliable enough to do things like stream HD videos. 5G is that it can connect more devices to more powerful networks with a lot less latency than 4G.
https://mashable.com/article/low-mid-band-mmwave-5g-explained/
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