Balances

This represents the balance that should be displayed when asked "how much do I own right now?".

It represents the amount currently owned, including things that may not be owned soon (e.g. in-flight outgoing payments, in-flight withdrawals, commit fees, etc.). It really is a snapshot of what is officially owned at this instant.

This represents the balance that should be displayed when asked "how much can I send on Lightning right now?".

It represents the amount currently available to be sent on the Lightning network. We remove from the balance all the funds that are temporarily locked (e.g. channel reserves).

This represents the balance that should be displayed when asked "how much money can I withdraw on the Bitcoin network right now?".

It represents the amount currently available to withdraw and is usually equal to the owned_balance but it does not include in-flight operations (which would likely succeed and therefore likely make your withdrawal fail).