What makes the difference, if you connect a pc/laptop to the modem, or you connect a router to the modem.
There is no difference.
In both cases, you have to configure the device, connected to the modem, to authenticate to your ISP.
On a pc/laptop, you might use a special modem driver, where you can configure, how to authenticate to the ISP.
If you connect the router to the modem, you have to configure the router, to authenticate to your ISP.
In that case, computers connected to the router, do not need special modem drivers. The requests from a computer to the internet will be forwarded to the internet, from the router.
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