Immunology is a dynamically evolving discipline integrating the knowledge of molecular and cell biology, physiology, histology and functional morphology (in the context of evolution and ontogenesis) relevant to the immune system. Immunology covers all levels of biological knowledge from molecules (cytokines, immunoglobulins, receptors, signaling molecules), cells (a wide array of immunocompetent cells), whole organisms (having transgenic animal models in use and recently a microbiome influence and interaction with immune system is being investigated) and communities (evolution of immune mechanisms, e.g. frequencies of different alleles regulating the immune response within a population).

Clinical immunology is an important emancipated immunology specialization, for which human beings are the object of research and application.