The process that increases low cytoplasmic concentrations in order to activate specific, essential events required by the cell is defined as calcium signaling. It uses calcium ions (Ca2+) to communicate and carry out intracellular processes often as a step in signal transduction. Calcium signaling plays a crucial role in the regulation of a diverse set of essential functions within the human body. The management of various neurodegenerative disorders such as Alzheimer's disease (AD), Huntington's disease (HD), and Parkinson's disease (PD) requires calcium signaling. It has been observed that disruption in calcium signaling may lead to synaptic deficits which further leads to accumulation of Aβ plaques and neurofibrillary tangles. Calcium plays an important role in various biological processes and calcium signaling has been linked to various diseases. Therefore, it is currently being explored as a therapeutic target for various types of cancer. This book elucidates the concepts and innovative models around prospective developments with respect to the importance of calcium signaling in biology and medicine. It will serve as a valuable source of reference for those interested in this field of study.