Multi Jet Fusion (MJF) and Selective Laser Sintering (SLS) are two Rapid Prototyping Technologies belong to the Powder BED Fusion category. The build materials in these technologies are thermoplastic polymers(namely Nylon) which is in granular form. In both of these, the build materials are fabricated as layer-by-layer technique with thermally fusing polymer.
The main difference between MJF and SLS is the heat source. MJF uses Infrared light where as SLS uses CO2 laser. Also in SLS each cross section is fused point by point, where as in MJf fusing takes place line-wise method. There are many other differences between these technologies with respect of accuracy, materials, cost and workflow.