Due to their excellent magnetic characteristics, hard ferrites have many high-tech applications. Keywords: Hard Ferrites, Synthesis, BaFe12O19, SrFe12O19, Magnetization, Miniaturization, EMI Shielding, Ferrofluids, Nanomaterials, Nano-Floating Gate, Permanent Magnets, Recording Media, High-Frequency Antenna, Radar Applications, Memory Devices. Spin Transmission, Spinel Model, Synthesis Methods.