Base vs. Solana

01

Why two addresses

Base is a network built on top of Ethereum, run by Coinbase; Arbitrum, Optimism and Polygon are built on Ethereum too. BNB Chain is a separate network, started by Binance, that isn't built on Ethereum but uses the same kind of address. Solana is a separate network known for speed and low fees, with a different kind of address.

So Base, Arbitrum, Optimism, Polygon and BNB Chain share one address in Viru, and Solana has its own. Tokens don't cross between networks on their own. USDC on Base and USDC on Solana are two different tokens, each worth a dollar, each living on its own network.

02

In practice

Pick the network that has the token you want; the Swap screen has a switch at the top for exactly this. On Base, Arbitrum, Optimism and Polygon a trade's fee usually comes out of the cash you pay with. BNB Chain has no cash on Viru: coins there are swapped for one another, and trades and sends pay a small fee in BNB. On Solana, Viru pays a trade's fee when it can; otherwise that wallet needs a little SOL.