Consensus must be reached for the transaction to be approved.
Answers
In most of the cases, they have the long chain for the transactions must be accepted with all the nodes and the main Consensus to be reached.
Moreover, this is not always true. The protocol will be introduced and can be allowed to the trustless and may distribute with Consensus. They will have a smaller group to preserve the blockchain to include and founded with the most community to rollback and reverse the effects.
Answer:
For any transaction to be complete there must be a consensus between the giver and the taker else the transaction may be termed as failed.
In Blockchain technology, the consensus is one f the primary factors to avoid double spending, and the proof of work is one of the most popular methods of evaluation of consensus.
In order to seal the deal, there must be some trust and some proof and make the transaction successful.