Immunology is the scientific study of the immune system and its role in protecting the body from biological and non-biological threats. Although relatively young as a distinct discipline, immunology has developed from several fields, including microbiology, biochemistry, genetics, and pathology.
The immune system functions as a complex defense network, recognizing and responding to foreign or abnormal entities, including infectious microorganisms, inert foreign substances, and transformed cells such as tumor cells. The effective functioning of this system results in immunity, a term derived from the Latin immunitas, meaning “exemption” or “freedom from.”