This paper reviews all the generations of technologies deployed in wireless telecommunication systems, starting from 1G, over 2G (continental standards) and 3G (almost worldwide accepted standards), finally focusing on 4G (the first worldwide accepted standard) also known as LTE (Long Term Evolution). Special attention is given to the pivotal influence of WiMAX, it being the first standard to spearhead the 4G technology, and how WiMAX both paved the way and caused acceleration to ensure a timely development, standardization, and introduction of LTE. Finally the article describes the transformation of the LTE technology from the initial version, also called 3.9G, to a true 4G standard, also called LTE Advanced.