The article reviews the current status of research on (III,Mn)V diluted magnetic semiconductors, focusing on the microscopic origins of ferromagnetism and the materials science of growth and defects. It highlights the progress in understanding the ferromagnetic properties of (III,Mn)V compounds, particularly (Ga,Mn)As, and discusses the challenges in achieving high Curie temperatures. The review covers the historical development, from the initial discovery of ferromagnetism in (III,Mn)V compounds to the recent advancements in growth techniques and material quality. The theoretical approaches, including first-principles calculations and effective Hamiltonian theories, are discussed, along with the experimental evidence supporting the models. The article also explores the magneto-transport and magneto-optical properties of these materials, emphasizing the role of valence band holes in the magnetic order. Finally, it addresses the potential applications of ferromagnetic semiconductors in microelectronic technologies and the ongoing efforts to enhance their performance.The article reviews the current status of research on (III,Mn)V diluted magnetic semiconductors, focusing on the microscopic origins of ferromagnetism and the materials science of growth and defects. It highlights the progress in understanding the ferromagnetic properties of (III,Mn)V compounds, particularly (Ga,Mn)As, and discusses the challenges in achieving high Curie temperatures. The review covers the historical development, from the initial discovery of ferromagnetism in (III,Mn)V compounds to the recent advancements in growth techniques and material quality. The theoretical approaches, including first-principles calculations and effective Hamiltonian theories, are discussed, along with the experimental evidence supporting the models. The article also explores the magneto-transport and magneto-optical properties of these materials, emphasizing the role of valence band holes in the magnetic order. Finally, it addresses the potential applications of ferromagnetic semiconductors in microelectronic technologies and the ongoing efforts to enhance their performance.