This paper reviews the advancements and challenges in dry and noncontact biopotential electrodes for clinical applications. Traditional wet Ag/AgCl electrodes are widely used but have limitations in comfort and mobility. Dry and noncontact electrodes offer solutions to these issues but face their own set of challenges, such as noise, motion artifacts, and friction. The paper provides an electrical model for dry, insulated, and noncontact electrodes, analyzing their performance limits and comparing different electrode types. It highlights the importance of minimizing electrode resistance and capacitance in certain contexts. The review also discusses the latest developments in dry and noncontact electrode technologies, including their applications in cardiac and neural monitoring. Despite the progress, the paper identifies ongoing challenges, such as motion artifacts and noise, and suggests future research directions to improve the reliability and usability of these electrodes for clinical use.This paper reviews the advancements and challenges in dry and noncontact biopotential electrodes for clinical applications. Traditional wet Ag/AgCl electrodes are widely used but have limitations in comfort and mobility. Dry and noncontact electrodes offer solutions to these issues but face their own set of challenges, such as noise, motion artifacts, and friction. The paper provides an electrical model for dry, insulated, and noncontact electrodes, analyzing their performance limits and comparing different electrode types. It highlights the importance of minimizing electrode resistance and capacitance in certain contexts. The review also discusses the latest developments in dry and noncontact electrode technologies, including their applications in cardiac and neural monitoring. Despite the progress, the paper identifies ongoing challenges, such as motion artifacts and noise, and suggests future research directions to improve the reliability and usability of these electrodes for clinical use.