What is consensus?

[Asoevjen]

Often I come across this word, but I do not fully understand what it means when applied to the blockchain. An agreement between miners?

[SeaBits]

Often I come across this word, but I do not fully understand what it means when applied to the blockchain. An agreement between miners?

I thnk you might be talking about this:

https://www.coindesk.com/coindesk-takes-consensus-2020-virtual

The event description: "This will enable more people from all over the world to participate and gather to discuss the most important topics of our time, coordinated by CoinDesk’s experienced journalists and moderators in a rolling live TV-like experience accessible from anywhere in the world."

If this is what your talking about... think of it as a group of 'experts' that will virtually discuss a wide range of topics about the different cryptos, technology, maybe legal stuff?

[bitcoinst]

It is amazing that you were not too lazy to spend time and type your question here, although if you had done the same action in Google you would have immediately received all the necessary answers.

Without going into details, this is a way to come to an agreement. Blockchain, as a rule, is a decentralized environment, and for its normal functioning,
it is necessary that all network participants are in consensus with each other. In other words, consensus is an algorithm a set of rules and functions that allow network participants to agree.
There is also the concept of a protocol, which is sometimes confused with consensus. The protocol is the initial rules of a particular blockchain, while consensus is the algorithm by which these rules work.

There are several types of consensus algorithms; all information about them has long been on the network. I will only mention the most basic ones that you have probably already heard about.

PoW (Proof of Work):
Example: Bitcoin.
The main feature is protection against Sybil attack.
The main disadvantage is that for the operation and security of the network, it is necessary to perform calculations requiring large energy costs.
There is also the problem of centralizing the hash rate.

PoS (Proof of Stake):
Example: DASH, NEO.
The main feature is there is no need to have computing power, it is enough to have a certain number of coins on the balance.
The main disadvantage "Nothing at Stake" problem.

You can delve into the technical details of the above algorithms here. https://bitfury.com/content/downloads/pos-vs-pow-1.0.2.pdf

[pooya87]

consensus: https://bitcointalk.org/dec/p1.html

consensus rules refer to the set of rules that define bitcoin. each node enforces these rules and if they find a block or transaction that doesn't follow these rules they will reject that as invalid. for example a transaction can not spend more coins than the total of its inputs or nowadays a block can not have a reward bigger than 12.5+total fees in that block.

keep in mind that miners aren't even involved in enforcing consensus rules. miners are just workers. they are like employees that follow the rules of the company that has hired them (that would be all the full nodes) and they can't change the rules.

[Yourhomeboy]

This link will help https://www.investopedia.com/terms/c/consensus-mechanism-cryptocurrency.asp

Just like we know the definition of consensus to be as a general agreement. In cryptocurrency, it is used for record-keeping and the various participants of the blockchain must agree that all transactions are legit. They are different types of consensus like the ones above including POC proof of capacity. This allows for sharing memory to the contributing node on the blockchain network.

[Wenbing]

I expect you to have use google to get answers to this question before asking from a position of an improved knowledge..

I have conduct a google search for you. Below is the Link;
https://en.bitcoin.it/wiki/Consensus

Consensus in a nutshell means an agreement that the nodes in a block chain has before adding a block to the network.