Electrochemistry is regarded as a mature scientific discipline, having a distinguished two-hundred-year-old history. The science of electrochemistry is concerned with electron transfer at the electrode interface. It has strong links to many other fields of science. Electrochemical concepts proved particularly fruitful for studying and interpreting a number of very important processes from analytical chemistry to batteries sciences.The objective of this work is to provide a sound understanding of the fundamentals of electrode reactions and the principles of electrochemical methods, and to demonstrate their potential for solving real-life analytical problems.