Understanding the difference between delegation and participation is crucial to understanding the power the community has over the Cardano blockchain.
They are two separate concepts.
First you need to understand the Proof of Stake (Pos) consensus.
The proof of stake algorithm in Cardano is called Ouroboros. It is a consensus protocol that ensures the stability of the blockchain by proof of ownership of its native cryptocurrency to validate information on the network, be it economic transactions or data records.
Consensus means that the majority of participants agree on a certain version of the truth at a given point in time.
The Cardano protocol elects the nodes entitled to create blocks at each epoch (approximately 21500 blocks, over 5 days) . The election is a lottery, which is influenced by parameters (mainly the amount of delegation of each pool and a limitation on the number of pools per epoch) . In the election there is randomness, but not total randomness, but weighted randomness.
The selected nodes execute a cryptographic test on the block, and sign, (thus forging the block including the validated transactions) and all the other nodes verify the action to give consensus and include it in the blockchain.
Persistence and security
Persistence is the ability to add new blocks continuously. Security means that only valid blocks will be added. The two qualities complement each other.
All ADA holders have the right to participate in the Cardano consensus by creating active nodes to support the network. However, not all ADA holders have the ability or desire to actively participate in the consensus mechanism.
Most ADA holders do not operate a stake pool, but can participate by delegating their consensus power. It is not mandatory for all ADA holders to participate or delegate in the consensus, but if you are not participating or delegating you are losing your power on the blockchain.
That loss of power means that the network will be less decentralised, or put another way, if too few participate by creating validating nodes and too few delegate their participation, the network will be centralised, and all users of its platform will be at the mercy of those wills, as they could agree to validate transactions in an unfair consensus, and of course it won’t take too long for the functionality to collapse.
For a protocol to be considered secure, it must be certain that no one can change the history of the ledger. The ledger is distributed on many computers around the world. The 51% attack is an attack perpetrated by whoever or whoever has the majority stake in the consensus and can arbitrarily execute the validation of operations on the network.
While rewards are presented as a relevant interest in participation and delegation, it is not the only issue, and I would venture to say not even the main issue, it is only an economic incentive to give consensus.
Choosing a pool to delegate your funds implies the responsibility and the work of investing in what the validating node you choose does, whether it provides services or content to the community, whether it is transpartent in its actions by informing in advance about its changes in pledge and variable margin, or whether it has a social or economic purpose beyond the basic function of validation.
Would you vote for a corrupt politician in your country?
To know if he or she is a corrupt politician you need to inform yourself and do your own research.
Delegate to a pool implies giving your vote to the pool owner in the network consensus.
The Cardano community has power over consensus and over decentralisation.
I invite you to participate in the consensus with transparency and honesty, and to delegate with responsibility and research.