Abstract
The fundamental definition of immunity is the organism's ability to resist the invasion of micro-organisms and dangerous substances and even unaltered host components. The immune system defends our bodies against the danger of the threat by communicating with chemicals and cells, which are incredibly complex to separate, kill and eliminate potential threats and also can cause disease under some circumstances. The immune system made up of certain and non-certain systems. The non-certain immune system is consisting of two different types of mechanisms (cellular and non-cellular). A certain immune system is completely assisted by lymphocytes and agranular leukocytes. Immune dysfunction or reduced immune competence may be caused by a number of factors such as fatigue, malnutrition and simultaneous infections. Immune-related disorders include allergy, asthma, autoimmune conditions, auto-inflammatory syndromes, and immune deficiency syndromes. Different functions of different immune systems seem to have been the primary driving force in the development of immune systems as a pathogenic diversity defense mechanism. Evolution of immunity exists over various occasions of the host population lifespan and related to the evolution of pathogen and the frequency shifts in a person's lymphocyte clone during an infection. The data bases, books and the research published papers in indexed medical and immunological are our references to write the review.This article provides an overview guide in immunity, and describes the properties and classification of the immune system and different types of host defense mechanisms. Focusing on auto-immune diseases, immuno-inflammatory disorders can be categorized as auto-inflammatory or auto-immune inflammasome processes that differ in the presentation of the disease. Therefore, each disease has its properties based on how the immune cells function under certain conditions that result in the cell output becoming abnormal.