  Spontaneous magnetic order is a routine instance in three-dimensional (3D)
materials but for a long time, it remained elusive in the 2D world. Recently,
the first examples of (stand-alone) 2D van der Waals (vdW) crystals with
magnetic order, either antiferromagnetic or ferromagnetic, have been reported.
In this review, we describe the state of the art of the nascent field of
magnetic 2D materials focusing on synthesis, engineering, and theory aspects.
We also discuss challenges and some of the many different promising directions
for future work.
