Cody just moved to a new house and the Wi-Fi internet upstairs is super slow. Leo says that Cody could put another router upstairs. If he puts the router in bridge mode, it will extend the Wi-Fi signal. There's a new way to do this, however. It's called Mesh Networking which uses a secondary signal, and doesn't just pass along the original signal. Eero and Plume do this, as well as the NetGear Orbi. The Orbi is the most powerful and fastest. There's also the Ubiquity AmpliFi HD, which is called the best of the Mesh systems. Those are more expensive, though.
(Disclaimer: Eero is a sponsor)