Since 70's, Non Evaporable Getter (NEG) pumps have been adopted by R&D labs, research centres, the industry and in large physics projects (i.e., accelerators, synchrotrons, fusion reactors...). NEG pumps are very compact, light and vibration-free. They require minimal power and present reduced magnetic interference. Their large pumping speed for hydrogen, the main residual gas in UHV-XHV systems, and also all active gases, makes NEG pumps the ideal choice to get and maintain low pressure conditions in a variety of applications. The basic chemical and physical principle of operation of getter pumps, as well as their main practical features, will be presented with a special focus on their typical applications in accelerators, portable systems, surface science and other laboratory equipment.