On the Steem blockchain, a Steem witness is a user who has been elected by other users to validate transactions and produce new blocks on the blockchain. Steem witnesses play a critical role in the functioning and security of the Steem blockchain.

Witnesses are responsible for maintaining a copy of the blockchain, validating transactions, and producing new blocks every 3 seconds. They also have the ability to propose and vote on changes to the Steem blockchain's operating rules, known as hard forks.

To become a Steem witness, a user needs to run a server capable of handling the demands of validating transactions and producing new blocks. They must also receive votes from other Steem users, with the top 20 users by vote count becoming the active witnesses.

The role of a Steem witness is crucial in maintaining the integrity and security of the Steem blockchain. Without witnesses, the blockchain would be vulnerable to attacks and the transactions on the platform could not be validated. Therefore, it is important for Steem users to participate in the witness voting process and support reliable and trustworthy witnesses