Fork ID refers to a unique identifier used in cryptocurrency networks to indicate a divergence or split in the blockchain. This happens when changes or upgrades are made to the protocol that are not compatible with the existing version. When a fork occurs, it can create two separate chains: one that follows the original rules and another that implements the new changes. Each of these chains may have a different Fork ID to help users and nodes distinguish between them. This is especially important for wallets and exchanges that need to track which version of the blockchain they are dealing with.Fork IDs can also facilitate transactions and ensure that the right assets are attributed to the correct blockchain. In some cases, they may be accompanied by changes in coin names or symbols to further clarify which version of the forked currency is being used. Essentially, Fork IDs play a crucial role in maintaining clarity and organization during times of change within a blockchain network.