The orbi device is built to work with your existing router or modem. Setting up your orbi as an access point allows you to use the orbi wifi instead of your existing router’s wifi.
The Netgear Orbi is a Wi-Fi mesh system meant to give high-quality Wi-Fi coverage across your home for individuals who are unfamiliar with it. It’s really simple to set up, even if you want to connect your existing router to it. You’ll have Wi-Fi connectivity throughout your home when you connect your Orbi device to your ISP modem, and you’ll be able to walk around without losing signal.
https://orbirouterssetup.com/troubleshooting/netgear-orbi-setup-with-existing-router/
