This book is intended for senior level undergraduate and postgraduate students taking control engineering either as a major or service course. The practicing engineer would equally find it valuable. It will surprise readers if I state that unknown to a lot of people, control engineering principles are similar to all human, physical, physiology, biological, mental and economic activities. It can hence be stated that control engineering took after nature in ¿sensing¿ and ¿regulating¿ activities hence ensuring that what is required is what is obtained. To support these facts, basic terms commonly met in control engineering, have been defined in this book, solved examples have also been presented as guidance to readers.