Q: What is autoimmunity? A: Autoimmunity is an immune response directed to a substance (referred to as antigen) present in the body of the host. Q: What is autoimmune disease? A: It is a disorder caused entirely or in part by an autoimmune response.
OAuth is an open standard for authorization, commonly used as a way for Internet users to log into third party websites using their Microsoft, Google, Facebook or Twitter accounts without exposing their password.
In short, please. :-). Authentication = login + password (who you are). Authorization = permissions (what you are allowed to do). Short auth is most likely to refer either to the first one or to both.