The concept of fuzzy logic is based on the fuzzy set theory which tries to represent the vagueness. Due to ambiguity, real word problems are very complex in nature. We cannot solve multifaceted vagueness using classical set theory. The reason behind that is, in classical set theory element either belongs to or does not belong to a set. Solution to real world problems can be given using human expertise and knowledge and classical logic failed to do so. Fuzzy logic provide solution to such problems as it supports to multivalued propositions. Thus fuzzy logic is widely used for application development in many areas. In this book we tried to unveil the fuzzy logic concept. We have discussed various concepts like the difference between classical set theory and fuzzy logic, fuzzy set, membership function and its type, fuzzification, fuzzy rules, method of defuzzification, etc. Then we elaborate the concept of fuzzy inference system and its implementation using MATLAB Fuzzy Logic Toolbox.