What is a hash (TXID) of a transaction?

TXID (transaction ID, hash) is a transaction passport, a number by which it can be identified in the blockchain of a particular cryptocurrency, and consists of alphanumeric characters.
A transaction hash is assigned to each cryptocurrency transfer.
The transaction receives a TXID automatically, and the user will not even remember the identifier until problems begin – a delay in the transfer, the lack of funds in the recipient’s wallet, etc. In such cases, it becomes necessary to check the status of the transaction, find out at what stage the transfer is and whether it was recorded in the blockchain and confirmed. To track the status of a transaction, you need to use special services.