What is Information Theory?

According to the Merriam- Webster Dictionary, "information theory" is a theory that deals statistically with information, with the measurement of its content in terms of its distinguishing essential characteristics or by the number of alternatives from which it makes a choice possible, and with the efficiency of processes of communication between humans and machines. Information theory is most commonly measured in bits (a contraction of a binary digit, being either a zero or a one).  The sequence of the information content is defined by the number of bits used to transmit the sequence with use of an optimal encoding. An important part of measuring information is the theory of entropy, which is expressed by the average number of bits needed for storage.