What is the difference between Agonist and Antagonist?

The set of agonists and antagonists are muscle sets in the human body, which is opposite to each other in action. While one has one action, the other opposes. In pharmacology, agonist and antagonist are represented as agents who ignite a response. If there are many advocates of an issue or cause and one person opposes it, he or she is considered an antagonist. The antagonist is used in terms of drugs, pharmacology and characterized as a drug combining with receptors in the body, supporting the action of the drug. Agonists and antagonists are pairs that both play a significant role in chemistry inside the human body.