About Alexa & Siri.
Alexa and Siri are developed by different companies. Amazon gets the credit of Alexa while Apple's credit is Siri. What can they do for you? Well like assistant they can set up reminders, answer questions, play music etc. Alexa's skill in other field is also remarkable. Siri, on the other hand, can send text messages, make phone calls etc. Both are using applications poered by Artificial Intelligence.