@DavidTallTrees6 

The TP-Link Archer NX200 is a 5G router that can operate as a primary 5G/LTE connection and also function as a backup for a wired internet connection. When connected to a modem (cable, fiber, or DSL), the NX200 can use its 5G/LTE connection as a backup to ensure a continuous internet connection, according to TP-Link. This means if the primary wired connection drops, the NX200 will automatically switch to the 5G/LTE network to maintain your internet access. 
Here's how it works:

    Primary Connection:
    The NX200 can connect to the internet via a standard wired connection (cable, fiber, or DSL) through its Gigabit WAN/LAN port.
    5G/LTE Backup:
    When configured as a wireless router, the NX200's built-in 5G/LTE modem acts as a backup for the primary wired connection.
    Automatic Failover:
    If the primary connection fails (e.g., internet outage), the NX200 will automatically switch to the 5G/LTE network to keep you online.