Apple Introduces Siri on the iPhone 4S

Apple introduced Siri as a built-in feature of the iPhone 4S in October 2011 after acquiring the original Siri company the previous year. Instead of requiring users to navigate menus, Siri accepted spoken requests such as setting reminders, sending messages, or checking the weather.

Speech recognition converted audio into text, while natural-language processing tried to infer the user’s intent and extract relevant details such as dates, names, and locations. Many requests were processed on Apple’s servers rather than entirely on the phone, so network latency and service availability directly affected the experience.

Siri was limited and sometimes inaccurate, but it made voice assistants a mainstream smartphone feature. It also created a new interface problem: users had to learn what kinds of natural language the system could actually understand.