Modem vs gateway: which are you replacing?

A modem talks to your ISP; a router makes your Wi-Fi; a "gateway" is both in one box. Most rented ISP units are gateways. When you replace one, you either buy a gateway, or buy a modem and pair it with a router you choose.

Why the split usually wins

A separate modem + router lets you upgrade the Wi-Fi half without touching the modem half — Wi-Fi standards move faster than DOCSIS. It also survives an ISP switch better: the router carries your network settings anywhere, and only the modem is ISP-specific.

When a gateway makes sense

One box, one power brick, one thing to reboot. Several ISP approved lists include gateways, and for a small apartment on a mid speed tier the simplicity is worth more than the flexibility. Check the ISP page here for whether combos are on your ISP's list — some ISPs restrict them for phone service.

The one thing to check either way

Voice service. ISP home-phone offerings often require the ISP's own equipment or a specific telephony-enabled model — several ISPs on this site say so explicitly on their pages. If you have phone through your ISP, read that line on your ISP's page before buying anything.