# Raiden Glossary

## Payments and Transfers

- Available balance
The available balance of a channel participant is:

\(B_{available} = B_{participant} - B_{locked}\)

- Balance
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.

\(B_{participant} = P_{total\ token\ deposit} + P_{total\ tokens\ received} - P_{total\ tokens\ sent}\)

- Balance proof
Balance proof is any kind of message used in order to cryptographically prove on the blockchain what the latest transferred amount and locked amount received from a counterparty is.

- Channel capacity
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Taking the total amount of tokens deposited and subtracting the total amount of tokens withdrawn by both participants that have a channel open with each other.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.

- Hashlock
A hashlock is the hashed secret that accompanies a locked message:

`sha3(secret)`

.- Lock expiration
The lock expiration is the highest

`block_number`

until which the transfer can be settled.- Locked amount
The locked amount is the total amount of tokens one participant of a payment channel has locked in pending transfers towards his counterparty

- Locked balance
The locked balance of a channel participant is the sum of the locked amount for all pending transfers \(T_{pending}\).

\(B_{locked} = \sum_{k=0}^{N-1} T_{pending}\) where \(N\) is the number of pending transfers

- MediatedTransfer
A mediated transfer is a hashlocked transfer between an initiator and a target propagated through nodes in the network.

- Merkletree root
- Locksroot
The root of the

`merkle tree`

which holds the hashes of all the locks in the channel.- Payment
A payment in Raiden is the process of sending tokens from one account to another. Each payment has an initiator and a target and can be composed of multiple transfers.

- Payment channel
The on-chain payment channel between two Raiden nodes.

- Preimage
- Secret
The preimage, what we call the secret in Raiden, is 32 bytes of random cryptographically secure data whose keccak hash ends up being the hashlock.

- Reveal timeout
The number of blocks in a channel allowed for learning about a secret being revealed through the blockchain and acting on it.

- RevealSecret
The reveal secret message is sent to a node that is known to have an interest to learn the secret.

- Secret message
The secret message is a message containing the secret and used for synchronization between mediated transfer participants.

- SecretRequest
The secret request message is sent by the target of a mediated transfer to its initiator in order to request the secret to unlock the transfer.

- Settlement timeout
- Settlement window
The number of blocks after the closing of a channel within which the counterparty is able to call

`updateNonClosingBalanceProof`

with the latest balance proof they received.- Transfer
A transfer in Raiden happens each time tokens are sent inside a payment channel.

- Transferred amount
The transferred amount is the total amount of tokens sent from a participant’s account to the account of a counterparty.

## Participants

Overview of a payment with one mediator:

```
Transfer1 Transfer2
[Initiator] -----------> [Mediator] -----------> [Target]
Payer Payee Payer Payee
```

- Counterparty
The counterparty of a channel is the other channel participant with whom you have opened a channel.

- Initiator
The initiator is the Raiden node which initiates (starts) a payment.

- Payee
The payee is the participant who receives a transfer.

- Payer
The payer is the participant who sends a transfer.

- Target
The target is the Raiden node which receives a payment from the initiator.