There is no doubt that Apple was the first to introduce a digital assistant called Siri. That doesn't mean that other companies were not working on a similar feature for their devices. Google was also working on a assistant. Then Microsoft introduced Cortana, and later Amazon introduced Alexa.
Although Siri was introduced first to the iPhone 4s, the other digital assistants are now as powerful as Siri if not stronger as Apple tries to add more and more features to improve Siri.
With every iOS release Apple introduce new features, and commands to Siri for iPhone to make it more responsive to questions.
So what is a digital assistant, and what is Siri for iPhone? Siri is Apple's solution to assist people requests by voice. So instead of unlocking your iPhone and launching the weather channel to know the weather, you can simply say "Hay Siri, and ask how is the weather today", Siri will answer the question with the latest update about the weather. There is no need to unlock your iPhone or search for any app.
Or instead of unlocking your iPhone to Create an alarm, you can simply say "Hay Siri, wake me up tomorrow at 7am" That is it. An alarm will be created to wake you up at 7am. Again, you didn't have to even touch your iPhone.
Hay Siri is a new feature that was added to the digital assistant through several updates with iOS.
Before Siri, or the digital assistant, talking to a computer wasn't new. There always existed someway of voice recognition. On the iPhone, if you disable Siri, your default Voice Control will be active. Voice control is different than a digital assistant in that it is not as smart, and it doesn't follow a continous conversation.
Siri was originally introduced as an App in the Apple Store That you could download in 2010 and about to be published for Android, and Blackberry. However, later, Apple acquired Siri, and all future developments to other platforms stopped.
Siri for iPhone 4s was first impeded in iOS 5 and became part of the Apple iOS 5. The iPhone 4S was the only iPhone at that time to support the digital assistant. It was an exclusive feature and a selling feature to the new iPhone 4s. All previous iPhones 2G, iPhone 3G, and iPhone 4 didn't support Siri.
Since then, Apple and third parties kept improving and adding features with every iOS update. Of course Apple was improving Siri through iOS updates, while hackers through iPhone jailbreak were also adding Siri hacks to add more features to Siri before Apple.
With iOS 10,and Siri for iOS 10, almost all the features are enabled. You can open an app, and access information from apps installed on your iPhone. Sirinow supports Home Kit, and Car Play too and it is part of iOS for the iPhone, Apple Watch and Apple TV.