Define of Siri
Siri is a set of built in voice commands that provides an easy way to interact with mobile phone via voice, instead of using touch or tap to access different functions of phone.
One simple example to tell you that what Siri can do. Siri can read your messages out to you when you receive them and it will reply using your words without you having to type a thing too.
Related Post Link:
other things it can do like you can play music, set alarm, open apps, tune in radio and lots of other stuff using voice commands.