This chapter explores the emergence and stabilization of magnetic order in two-dimensional materials, bridging theoretical constraints and recent experimental breakthroughs. While foundational theorems, such as the Mermin-Wagner theorem, suggest the absence of long-range magnetic or crystalline order in 2D systems with continuous symmetry, real materials can evade these constraints through mechanisms such as anisotropy, discrete symmetry breaking, and finite-size effects. The chapter outlines how these principles manifest in van der Waals magnets like CrI \(_3\) , CrGeTe \(_3\) , and FePS \(_3\) , the latter being among the first monolayer antiferromagnets discovered. Emphasis is placed on the role of spin-lattice coupling, which enables indirect probing of magnetic states through Raman spectroscopy and optical anisotropy. The discussion extends to the MPX \(_3\) family of materials, highlighting the diversity of magnetic ground states enabled by tuning exchange interactions and anisotropies. Finally, the chapter introduces noncollinear magnetic textures and their potential to drive ferroelectricity in systems like NiI \(_2\) , establishing a foundation for understanding multiferroic behavior in the 2D limit. This convergence of theory and experiment underscores the evolving landscape of low-dimensional magnetism and the opportunities it presents for fundamental studies and spintronic applications.