4g has to do with mobile phone and data communications.
An example of 4G is the cell network that smartphone or mobile modem owners can access to have faster data transfer speeds.
4G - Computer Definition
(4th Generation) The latest cellular technology generation. In 2010, the ITU officially designated LTE, WiMAX and HSPA+ as 4G technologies. See LTE, WiMAX, HSPA and cellular generations. 4G Speeds In 2014, various tests of carriers in the U.S. touting 4G capabilities reported average download speeds from 4 to 8 Mbps and upload speeds from 1 to 6 Mbps. Because the number of users in a cell is constantly changing, speeds vary as everyone shares the same bandwidth. As more customers frequent a cell, average speeds decline until more antennas are added. For the difference between 4G and Wi-Fi, see cellular vs. Wi-Fi.