Siri is a virtual personal assistant developed by Apple Inc., pre-installed on all of the company's devices. It was first introduced as an iOS app in February 2010 and later integrated into the iPhone 4S upon its 2011 release. At its core, Siri utilizes natural language processing to understand and respond to user commands and queries. Users can activate Siri by saying "Hey Siri" or by pressing the home button on older devices or the side button on newer devices.

One of Siri's primary functions is to assist users with hands-free tasks. It enables advanced features such as providing information on weather forecasts, delivering sports scores and stock prices, searching the internet using voice commands, translating phrases into different languages, solving mathematical equations, and even telling jokes.

The original American voice of Siri was recorded in July 2005 by actress Susan Bennett.