High Quality Content by WIKIPEDIA articles! Siri (pronounced /ˈsɪri/) is an intelligent software assistant and knowledge navigator functioning as a personal assistant application for iOS. The application uses a natural language user interface to answer questions, make recommendations, and perform actions by delegating requests to a set of web services. Siri claims that the software adapts to the user's individual preferences over time and personalizes results, as well as accomplishing tasks such as making dinner reservations and reserving a cab.