Using nongrid random to place objects. Objects are created using the probability factor of mask and remoteness from other objects.
Use Cases:
Usually it takes more time to place generate objects this way, so it's recommended to use Random node only if the desired effect could not be achieved with Scatter  for example, if scattered objects are still too uniform.
Zero Uniformity: Scatter (left) and Random (right)
Inputs:
Random node can receive the probability mask. Mask values factor will be taken into account when placing an object. The higher the pixel values in some of the map area  the more objects will be spawned there.
Properties:

Seed: a number used to initialize pseudorandom noise generator. If two generators use equal seed numbers the resulting pattern will be the same.

Density: the quantity of scattered objects per a square kilometer (100x100 units). Note that since are objects are placed at random within terrain tile + margins the total number of objects within tile itself might differ both in bigger and smaller sides.
Density: 10, 100, 1000Unlike Scatter, it will not create objects on any of the terrains if density is below 1.

Uniformity: the influence of the distance factor in randomly placing the object. If 0 it will place objects absolutely at random, disregarding already placed ones. In 1 it will try to find the equidistant place from already existing objects.
Note that the true "grid" uniformity, like the one in Scatter, is not achievable here.
Bigger uniformity values slow down performance.