SCARA is an acronym - "Selective Compliance Assembly Robot Arm". It first was used for robot arm motion.

Usually SCARA mechanics is faster and more accurate than Cartesian mechanics. There is not any belt pulleys or other parts, which often need to be tighten. So the 3D printer with SCARA mechanics provides high repeatability. Once printed detail can be duplicated many times (even in a month). And the printer doesn't need to be maintained every time. One calibration per month is more than enough.

Here is video demonstration of printer's arms moving:

Levers of this printer are made from an aluminium alloy, with a usage of combined journal and thrust bearings, the mechanism is equipped by a unit of automatic backlash eliminating.
The main advantage of such printer - printing quality is stable and it doesn't require permanent adjusting.Another advantage - it is very compact in compare to the same printing area prunters. And it works very silent.

Please, refer to this website to get more information: https://3dlaboratorio.es/eng/3d-printers.htm