Q:

Push notification: api.development.push.apple.com versus api.sandbox.push.apple.com

For sending pushes over the development network why does one encounter frequent references to both of these apis:
api.development.push.apple.com:443
api.sandbox.push.apple.com:443
Is there any difference between them, the Apple documentation says to use api.sandbox.push.apple.com:443 (https://developer.apple.com/documentation/usernotifications/setting_up_a_remote_notification_server/sending_notification_requests_to_apns)
yet I see many examples using api.development.push.apple.com:443 instead. 
Why? 

A:

Looks like you can use both. 
https://api.development.push.apple.com/ and https://api.sandbox.push.apple.com/ has one HTTPS certificate (issued in 2019) with SANs:

DNS-name=api.development.push.apple.com
DNS-name=api.sandbox.push.apple.com
DNS-name=api.qa1.push.apple.com
DNS-name=api.qa2.push.apple.com

But CN of this cert is api.development.push.apple.com )

