This Paper give introduction to Fuzzy Logic and Various application in different branch of Engineering and Research. Fuzzy Logic is Applied branch of Mathematics in which Lots of research is taking place. Fuzzy Logic works on "if.....then.....".Fuzzy Logic gives the idea that members are not restricted to T or F definition. The concept of Fuzzy Logic is used in the various fields as Artificial Intelligence, Aerospace, Automotive Business, Defence, Electronics, Finance, Industrial Sector, Marine Sector, Manufacturing, Medical, Securities, Transportation Pattern Recognition and Classification, Psychology, etc. The whole field of Engineering as civil Engineering, Mechanical Engineering, Industrial Engineering real Reliability theory, Robotics, Computer Engineering is broad to be covered here in a comprehensive way.