This article reviews the domain aspects of multi-ferroic materials, which exhibit ferroelectricity, ferromagnetism, and/or ferroelasticity in the same phase. It focuses on materials where the magnetic point group has been reliably established through studies on single crystals and single domains. The majority of known multi-ferroic materials belong to the boracite family, while data on perovskites and other classes is limited. Polarized light microscopy is essential for studying multi-ferroics, especially when ferroelasticity is involved. The article discusses the structural and symmetry requirements for simultaneous ferroelectricity, ferromagnetism, and ferroelasticity, and presents examples of materials that meet these criteria. It also addresses the experimental challenges in studying multi-ferroics, including the need for precise control of domain structures and the difficulties in determining magnetic point groups. The article highlights the importance of understanding the interplay between ferroelectric, ferromagnetic, and ferroelastic properties in these materials, and the role of symmetry in determining their behavior. It also discusses the potential of multi-ferroic magnetoelectrics for applications in devices that exploit the magnetoelectric effect.This article reviews the domain aspects of multi-ferroic materials, which exhibit ferroelectricity, ferromagnetism, and/or ferroelasticity in the same phase. It focuses on materials where the magnetic point group has been reliably established through studies on single crystals and single domains. The majority of known multi-ferroic materials belong to the boracite family, while data on perovskites and other classes is limited. Polarized light microscopy is essential for studying multi-ferroics, especially when ferroelasticity is involved. The article discusses the structural and symmetry requirements for simultaneous ferroelectricity, ferromagnetism, and ferroelasticity, and presents examples of materials that meet these criteria. It also addresses the experimental challenges in studying multi-ferroics, including the need for precise control of domain structures and the difficulties in determining magnetic point groups. The article highlights the importance of understanding the interplay between ferroelectric, ferromagnetic, and ferroelastic properties in these materials, and the role of symmetry in determining their behavior. It also discusses the potential of multi-ferroic magnetoelectrics for applications in devices that exploit the magnetoelectric effect.