The article reviews the recent advancements in terahertz (THz) communications, highlighting the role of photonics in developing first-generation THz communication systems. It discusses the increasing demand for higher wireless communication speeds and the limitations of existing technologies, such as millimeter-wave (MMW) frequencies. The article emphasizes the potential of THz waves, which offer much higher bandwidths, but also faces challenges like atmospheric attenuation and signal power limitations. Photonics-based approaches, particularly using photonic devices and III/V semiconductors, have been key in achieving high data rates and modulation indices. The article also explores the integration of photonic and electronic technologies, the development of advanced antenna systems, and the comparison with free-space optics (FSO) communications. Finally, it outlines future prospects and challenges, including the need for more powerful transmitters, efficient receivers, and advancements in interconnect technologies, to fully realize the potential of THz communications.The article reviews the recent advancements in terahertz (THz) communications, highlighting the role of photonics in developing first-generation THz communication systems. It discusses the increasing demand for higher wireless communication speeds and the limitations of existing technologies, such as millimeter-wave (MMW) frequencies. The article emphasizes the potential of THz waves, which offer much higher bandwidths, but also faces challenges like atmospheric attenuation and signal power limitations. Photonics-based approaches, particularly using photonic devices and III/V semiconductors, have been key in achieving high data rates and modulation indices. The article also explores the integration of photonic and electronic technologies, the development of advanced antenna systems, and the comparison with free-space optics (FSO) communications. Finally, it outlines future prospects and challenges, including the need for more powerful transmitters, efficient receivers, and advancements in interconnect technologies, to fully realize the potential of THz communications.