The history of cellular technology starts at Bell Labs in the 1960's and 70's where they began to iron out the details on what a commercial cellular network would be. A cellular network is a network of base stations, or antennas, that form large pockets (cells) of radio signal coverage that overlap. With a technology called "handover," if you made a call using one base station, and you then moved out of that base station's range and into another base station's area, your call could be "handed over" to the base station that was closer to your location. These base stations allowed you to make calls to other cellular phones or to wired landline phones.
Over the years, the evolution of cell phone technology has been broken up into "generations." It started with the first generation (1G), and it continues to the upcoming fourth generation (4G). In the beginning, cell phones weren't much more than huge walkie-talkies. Over time, though, they evolved into the data powerhouses that we carry around in our pockets.