What is the difference in the role of an operator and the role of a promoter

An operator is a segment of DNA that a regulatory protein binds to. It is classically defined in the lac operon as a segment between the promoter and the genes of the operon. A repressor or activator can bind to an operator. 

Promoter is the RNA polymerase binding site

The answer is cjust typing because the minimum is 20 bl bl bl

Air enters through the nose (and sometimes the mouth), moves through the nasal cavity, the  pharynx, the  larynx, enters the  trachea, moves through the  bronchi  andbronchioles  till the alveoli.