> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cosmos.network/llms.txt
> Use this file to discover all available pages before exploring further.

# State Transitions

> A successful fungible token send has two state transitions depending if the transfer is a movement forward or backwards in the token's timeline:

## Send fungible tokens

A successful fungible token send has two state transitions depending if the transfer is a movement forward or backwards in the token's timeline:

1. Sender chain is the source chain, *i.e* a transfer to any chain other than the one it was previously received from is a movement forwards in the token's timeline. This results in the following state transitions:

   * The coins are transferred to an escrow address (i.e locked) on the sender chain.
   * The coins are transferred to the receiving chain through IBC TAO logic.

2. Sender chain is the sink chain, *i.e* the token is sent back to the chain it previously received from. This is a backwards movement in the token's timeline. This results in the following state transitions:

   * The coins (vouchers) are burned on the sender chain.
   * The coins are transferred to the receiving chain through IBC TAO logic.

## Receive fungible tokens

A successful fungible token receive has two state transitions depending if the transfer is a movement forward or backwards in the token's timeline:

1. Receiver chain is the source chain. This is a backwards movement in the token's timeline. This results in the following state transitions:

   * The leftmost port and channel identifier pair is removed from the token denomination prefix.
   * The tokens are unescrowed and sent to the receiving address.

2. Receiver chain is the sink chain. This is a movement forwards in the token's timeline. This results in the following state transitions:

   * Token vouchers are minted by prefixing the destination port and channel identifiers to the trace information.
   * The receiving chain stores the new trace information in the store (if not set already).
   * The vouchers are sent to the receiving address.