How does iPhoneXsMax wake Siri up?

We can wake up the phone by pressing the power button on the right and say "Hey, siri" to it.

After waking up, you can tell your mobile phone your requirements. Siri will help you find the information you want or turn on the music player.

For example, say to siri, "I want to hear a joke." So siri tells you a joke. Siri is much more sensitive than other mobile assistants. At the same time, you can also ask him to help you search for dramas and play videos. Very convenient.