RPC & networks
Networks and Remote Procedure Call (RPC) is the core source of ethereum information. All data displayed in the wallet can generally be derived from RPC requests.
Users should be able to configure their networks, deciding exactly where their information is sourced from and how its loaded, be this via JSON-RPC, a lightclient, or other methods.
Adding a new network
In addition to the user configuring the network settings themselves, dApps may surface buttons to "add a network to wallet". You can read more about this on the network discovery section.
Here is an example of what a wallet would show when a dApp requests a new network to be added.
This site wants to add a network to your wallet (wallet_addEthereumChain, EIP-3085).
An important note when accepting requests from dApps is that the "RPC URL" is the ultimate source of truth of the data. Meaning if a user already had a network configured, we should be careful.