The Cardano node is the top-level component within the network. Network nodes connect to each other within the networking layer, which is the driving forcefor delivering information exchange requirements. This includes new blockdiffusion and transaction information for establishing a better data flow.Cardano nodes maintain connections with peers that have been chosen via a custompeer-selection process. By running a Cardano node, you are participating in andcontributing to the network.
How does it work?
Stake pools use the Cardano node to validate how the pool interacts with thenetwork and are responsible for transaction processing and block production.They act as reliable server nodes that hold and maintain the combined stake ofvarious stakeholders in a single entity.
Producing a block
The goal of blockchain technology is the production of anindependently-verifiable and cryptographically-linked chain of records (blocks).A network of block producers works to collectively advance the blockchain. Aconsensus protocol provides transparency and decides which candidate blocksshould be used to extend the chain.
Submitted valid transactions might be included in any new block. A block iscryptographically signed by its producer and linked to the previous block in thechain. This makes it impossible to delete transactions from a block, alter theorder of the blocks, remove a block from the chain (if it already has a numberof other blocks following it), or to insert a new block into the chain withoutalerting all the network participants. This ensures the integrity andtransparency of the blockchain expansion.
Slots and epochs
The Cardano blockchain uses the Ouroboros Praos protocol to facilitate consensuson the chain. Ouroboros Praos divides time into epochs. Each Cardano epochconsists of a number of slots, where each slot lasts for one second. A Cardanoepoch currently includes 432,000 slots (5 days). In any slot, zero or moreblock-producing nodes might be nominated to be the slot leader. On average, onenode is expected to be nominated every 20 seconds, for a total of 21,600nominations per epoch. If randomly elected slot leaders produce blocks, one ofthem will be added to the chain. Other candidate blocks will be discarded.
Slot leader election
The Cardano network consists of a number of stake pools that control theaggregated stake of their owners and other stakeholders, also known asdelegators. Slot leaders are randomly elected from among the stake pools. Themore stake a pool controls, the greater the chance it has of being elected asa slot leader to produce a new block that is accepted into the blockchain. Thisis the basic concept of proof of stake (PoS). To maintain a level playing field, and prevent a situation where a small number of very large pools control the majority of stake, Cardano has an incentive system that discourages delegation to pools that already control a large portion of the total stake.
Transaction validation
When validating a transaction, a slot leader needs to ensure that the sender hasincluded enough funds to pay for that transaction and must also ensure that thetransaction’s parameters are met. Assuming that the transaction meets all theserequirements, the slot leader will record it as a part of a new block, whichwill then be connected to other blocks in the chain.
Cardano node course
The IOG Academy provides a series of video tutorials on YouTube that describe a variety of topics from installing the node to using many of its features.
