https://www.cnbc.com/2019/03/30/how-to-switch-airpods-between-iphone-mac-and-ipad.html

I recently spoke with Apple about its second-generation AirPods and, during the conversation, Apple told me something I never knew: once connected to your iPhone, they're paired with your Apple account. That means, as long as you're logged-in to other devices like your Mac or iPad, you can easily switch to using your AirPods for audio.

You don't have to manually re-pair them with each device. Instead, you just need to pop into the Bluetooth settings on each device and choose the AirPods. And the second-generation AirPods do this faster than the first model, allowing you to switch from music on one device to audio on another in less than two seconds.