1.The term “consensus determines the truth” when used in reference to blockchain means that truth is derived from several trust-less and verifiable ledgers.
What does it mean when we say that in blockchain, consensus determines the truth?
It means that consensus confirms that each transaction added to blockchain is legit.
How is this different from how truth is determined in a central database?
In a central database truth is determined by a small group of people that can manipulate data and decide for what ''truth'' is. In blockchain, truth is determined by a whole network.It means that multiple parties (or computers in a network) need to agree for a decision to be made. For example, a payment transaction will only go ahead if there is consensus within the network that the party initiating the payment in fact has sufficient funds to do so.
It is different insofar as truth is based on network consensus, as opposed to a centralized database where truth is based on matching a (single) record within a centrally controlled dataset.
Nodes in the network come to agreement on weather a transaction on the blockchain is true or false this works due to the decentralization of the the network.
Truth in a central database can be manipulated by the authority of that database.
All transactions are confirmed by the network before being added to the blockchain. All information is available to everyone removing the trust.
Information is passed along the chain so the element of trust is needed between parties.
1 - All computers running the blockchain must agree or consent to the transaction for it to be true and accepted to be written to the stone of information.
2 - Truth cannot be verified in a central database. They always have a margin of error, unlike blockchain.
What does it mean when we say that in blockchain, consensus determines the truth?
Several nodes must validate (confirm the ‘truth’) a transaction before it is committed to the Blockchain.
How is this different from how truth is determined in a central database?
Hmmm… would you unquestionably TRUST anything from a central anything? The difference is that TRUST from many vectors all incentivized to tell the TRUTH is much more powerful than 1 data point from a centralized form (e.g. database). Maybe we need to apply this model to the mainstream media 
Now that’s a valuable use case for blockchain!!!
What does it mean when we say that in blockchain, consensus determines the truth?
The nodes come to a collective agreement and only accept validated transactions into the blockchain.
How is this different from how truth is determined in a central database?
There is only one validator in a central database while there are multiple validating nodes that come to a consensus in a decentralized database.
1: Since every system within the blockchain is required to validate data, the integrity of the truth is preserved.
2: On a centralized database, whomever has access and authority can make changes, add, or subtract data at will. Thus, there is no consensus or network validation.
Majority of nodes need to reach consensus that the transaction is true. The reward incentive for being truthful is what makes nodes behave in a good way.
In central database one or few people can decide what is the “truth” and behave in a way that will only benefit them.
*What do we mean in a block chain, consensus determines the truth?
A consensus is the majority deciding on the truth. When a transaction comes through in a Block chain, each computer on the network, will decide whether to accept the details , and allow them to register. There is no need to trust any one party, because the transaction has been verified many times, so the truth is confirmed.
*How is this different from how truth is determined in centralised databases?
I am not sure about all professional databases, but the ones I have worked on and what I have researched determin that individuals in different parts of the organisation can input information independently. Therefore, the system requires trust, and is open to the possibility of human error and mendacity. The only recourse would be supervision by the central authority, which is far less reliable and efficient.
What does it mean when we say that in blockchain, consensus determines the truth?
Consensus means that many computers in the network agree that a transaction is legit by comparing the block they receive. If everyone agrees it is put in the ledger. By checking a transaction with many computers, the risk for a corrupt entry is removed, thus it is the truth.
How is this different from how truth is determined in a central database?
A central database only needs one entry of data. When that entry is not checked with any other source that could have verified that this entry is correct, or not correct, there is no verification taking place.
All the ledgers in the network must verify if a transaction is true or not.
In a decentralized network there are several parites involved in a decision and people are getting incentivised to tell the truth.
In a central database they can easily lie and manipulate the truth to get what they want.
The blockchain network accepts, confirms, every recorded transaction…its ‘consensus’ validation of every transaction negating the need to depend on trust…trustlessness.
Central database information is dependent of the truthfulness of data source.
Consensus is truth finding or verifying by many around globe and not by a dictator, middleman, central authority or from one location as with a centralized database
What does it mean when we say that in blockchain, consensus determine the truth?
It means that through collective agreement in accepting whether something true or untrue that cheating is not possible. That any transaction is not determined by trust but through verification provided by the collective agreement.
How is this different from how truth is determined in a central database?
In a network there include various numbers of players that make up a particular database, it is very difficult to verify or find the truth of such claims on a product. It is relied upon trust and not truth.