An internal transaction or message is a consequence of an EOA while interacting with a contract address. This often results in the transfer of Ether. For the most part, smart contract transactions are traceable but irreversible.
These tractions are made through externally owned accounts or EOAs, which are held by the individuals. The smart contract tractions trigger the byproduct known as an ‘internal transaction.’
With a single smart contract, there are possibilities of tens and hundreds of internal transactions in the form of value transfers. Although the internal transactions appear on the main ETH transaction history, they are never visible.