Extrusion Technologies (FDM/FFF)
Because a vast majority of the 'accessible' desktop 3D printers use extrusion-based technologies, they are what non-engineers / 3D printing geeks think of as soon as you mention '3D printer'. While this 3D printing technology holds sway on the desktop, it is also a workhorse of the industrial setting too, with a broad range of useful materials options from polylactic acid (PLA) through acrylonitrile butadiene styrene (ABS) to Polyether ether ketone (PEEK) and various composite options.