The balance determines how many tokens one specific channel participant holds.
You can calculate the balance by taking the total amount of tokens deposited, adding the total amount of tokens received and subtracting the total amount of tokens sent for a participant.
The channel capacity determines how many tokens a channel holds. You can calculate the capacity by either:
Taking the total amount of tokens deposited and subtracting the total amount of tokens withdrawn by both participants that have a channel open with each other.
Taking the sum of both channel participants balance.
A payment in Raiden is the process of sending tokens from one account to another. Each payment has an initiator and a target.
A payment channel allows for back and forth Raiden payments between participants without involving the actual blockchain. A payment channel in Raiden is always backed by an on-chain deposit of tokens.
The transferred amount is the total amount of tokens sent from a participant's account to the account of a counterparty.
The counterparty of a channel is the other channel participant with whom you have opened a channel.
The initiator is the Raiden node which initiates (starts) a payment.
The payee is the participant who receives a payment.
The payer is the participant who sends a payment.
The target is the Raiden node which receives a payment from the initiator.
A transfer in Raiden happens each time tokens are sent inside a payment channel.