Amazon Alexa is an AI (Artificial Intelligence) developed by Amazon, that allow the users to interact with it and ask to perform some particular tasks.
The range of tasks is very wide. It goes from setting up an alarm to stream music and videos.
Amazon Alexa is integrated in Amazon devices such as Amazon Echo.
The AI is always in standby mode and it activates on demand by pronouncing specific words, the default one is “Alexa”.
Of course the “wake-up” words are various and they can be changed accordingly to your needs.
Coming back to the tasks, as I stated the range is very wide. There are native tasks that are built-in, such as navigating the Internet. Other tasks or “skills” can be then activated on-demand using ad-hoc apps that can be downloaded on the Amazon store.