What Is a Router? (Router vs Modem Explained)

by Priya Nakamura Updated Apr 12, 2026

A router creates a local network and directs traffic between your devices and the internet. A modem connects your home to your ISP. Most people need both, though combo devices (gateways) include both in one box.

Router vs Modem

A modem translates the signal from your ISP (cable, fiber, DSL) into a digital signal your devices can use. A router takes that connection and shares it among multiple devices via WiFi and Ethernet. Think of the modem as the front door and the router as the hallway connecting all rooms.

Do I Need Both?

If you have a combo device (modem/router gateway) from your ISP, you don't need a separate router. But many people add their own router for better WiFi performance and features, using the ISP device in bridge mode.

Related Guides

Video Tutorial

For more information, see Wikipedia — TCP/IP.

Pro Tip: DNS is often called the phonebook of the internet. Switching to a faster DNS can improve your perceived internet speed significantly.

Key Takeaways

Private IPs (192.168.x.x, 10.x.x.x) are used inside your home network
DNS translates domain names to IP addresses
DHCP automatically assigns IPs so you don't have to
Your default gateway is your router's IP address

Frequently Asked Questions

What is the difference between a router and a modem?

A modem connects to your ISP and translates their signal. A router creates your home network and shares the internet connection among devices via WiFi and Ethernet.

Do I need a router if I have a modem?

You need a router to share the internet among multiple devices and create WiFi. Some ISP-provided devices combine both (modem/router gateway).

About Priya Nakamura

Priya is a telecommunications engineer and networking educator at RouterHax. With a background in ISP infrastructure and a Master's in Computer Networks, she explains complex networking concepts in plain English. Priya covers WiFi standards, protocols, IP addressing, and network architecture.