Bioimpedance is a technique that measures the resistance of biological tissues to the flow of electric current. This method is commonly used in medical and health-related fields to assess body composition, fluid distribution, and other physiological parameters. Bioimpedance analysis (BIA) involves applying a small, safe electrical current through the body and measuring the opposition to this current, which varies based on the tissue type and its properties. Different tissues in the body, such as fat, muscle, and bone, have distinct electrical conductivities and permittivities. Muscle tissue, for example, contains more water and electrolytes, and conducts electricity better than fat tissue, which is more resistive. By analyzing these differences, BIA can estimate the proportions of fat mass, lean body mass, and total body water. Bioimpedance is widely used due to its non-invasive nature, ease of use, and rapid results. It is applied in various contexts, from clinical settings for monitoring patients' hydration status and nutritional health, to fitness centers for body composition analysis. The book aims to shed light on some of the unexplored aspects of bioimpedance. Such selected concepts that redefine this area of study have been presented in this book. For all those who are interested in understanding bioimpedance, this book can prove to be an essential guide.