Upon connecting to a Wi-Fi network, you're redirected to a login screen and a request to accept terms of service before being connected.

What is this an example of?

captive portal

Explanation:

Captive portal -

It is a web page, which is opened along side the web browser which get displayed on to the fresh connected users of the Wi-Fi network, just before it gets the assurance to use the resources of the network, is known as captive portal.

Generally captive portal requires authentication or payment for access the internet resource.

Hence, from the question information, the example shown in the question is about captive portal.