Definition of Entropy The term entropy is often avoided because it contains a certain complexity. The phenomenon entropy, however, is constitutive for everything that is going on in our lives. A closer look is worth the effort. Entropy is a measure of information and it is defined as: Entropy is the information - known at micro, - but unknown at macro level. The challenge of this definition is: to understand what is meant by the micro and macro states and ​to understand why entropy is a difference. ​What is Meant by Micro and Macro Level? The micro level contains the