0 technology used in mobile phones before 4G or 5G that made it possible to use the internet, watch video, etc. 3G is short for "third generation":
1 abbreviation for third-generation: relating to or using a technology that gives mobile phone and computer users a high-speed internet connection as well as good video and other advanced features:
a 3G network
We can complete it step by step however long the road is and it can't be completed however short the road is if you don't even mark your footprint.