3G actually stands for “third generation”, as it is the third type of access technology that has been made widely commercially available for connecting mobile phones.
The first generation of mobile phones was launched in the 1980s, and transmitted across an analogue signal; these phones were large, brick-like devices that were often kept in a vehicle as they were impractical and inconvenient to carry around.
They were supplanted by the second generation in the 1990s, which now used a more reliable digital signal, and enabled the use of text messaging, or SMS (Short Message Service). However, the technology was still not robust or fast enough to deal with the thousands, and then millions, of consumers who wanted to use mobile phones; the signal could not carry enough data simultaneously, and there were many areas the signal did not cover. There was also a rapidly growing demand for transmitting data – using email and accessing the internet – across mobiles, which 2G was just not fast or reliable enough to manage. An intermediate technology – sometimes called EDGE or 2.5G – came next, but the technology rapidly moved on towards proper 3G.