As implied in the name, bridges allow one to easily migrate tokens from one chain to another.
***Please note: Not all tokens have adequate liquidity across multiple networks. Before migrating to a different network, please DYOR (Do your own research)!
Also: If you are using an 'unconfigured' wallet (like Metamask), you will need to manually configure the RPC and associated info for the network you want to use in your wallet. (1inch Wallet comes pre-configured and does this automatically for 1inch integrated networks).
For Optimism, BSC, and Polygon bridges, you will need to have some ETH in your Ethereum wallet to cover gas fees when converting.
To switch between Ethereum and Binance Smart Chain (BSC):
Simply click the "Bridges" Tab at the top of any page on the 1inch site, then select "BSC Bridge":
To switch between Ethereum and Polygon:
Click on the same "Bridge" tab as above, and select "Polygon Bridge".
To switch between Ethereum and Optimistic Ethereum:
Click on the same "Bridge" tab as above, and select "Optimism Bridge".
***Please note: Converting ETH from Optimism to Ethereum Mainnet involves a mandatory 7 day transfer period for all withdrawals.