A blockchain is a decentralized and distributed digital ledger that can record transactions across many computers in a peer-to-peer network. It uses cryptography to ensure the integrity and chronological order of the records and to verify the identities of those making transactions.
A peer-to-peer network is decentralized, meaning there is no central server or authority that manages the transactions. There are no single points of failure and trust is not required between peers. Each node has equal access to all information on the blockchain network.
A peer-to-peer network allows you to make transactions without having to rely on intermediaries such as banks or other financial institutions; this means they can be faster and more secure than traditional payment methods like credit cards or cash.
Consensus is the process by which blockchain networks agree on the same version of events. It’s used to ensure that all participants in a distributed system (the network) have the same information and agree on it.
Consensus algorithms are often divided into two categories: Byzantine Fault Tolerance (BFT) and Proof-of-Work (PoW). In BFT, there are multiple groups of computers working together to reach consensus, while PoW requires each computer on the network to solve an extremely difficult puzzle before being able to verify transactions.
The blockchain is a distributed ledger that functions as a public record of all transactions, which are stored in blocks. Each block contains information about a transaction and the previous block(s). The blocks are linked together using cryptography, which means they’re stored on different computers in different locations around the world. These computers use their own unique cryptographic keys to verify data integrity and authenticity before adding new information onto their respective copies of this shared ledger (or “blockchain network”).
Cryptography is used to connect every computer with its own copy of this shared ledger—and it can only be done by using hashes for verification purposes! Hashes are one-way functions that convert any given string into another string with some fixed length (usually 128 bits), such as “123456789012345678901234567890abcdefghijkmnopqrstuvwxyz”. This ensures each user has only one chance at generating an identical hash value when attempting to change any given piece of information within their own copy(s) within each system node.”
Blockchains are just peer-to-peer networks with a specific consensus algorithms and cryptography. The blockchain is a distributed database, where records are replicated across the network so that they cannot be modified without the agreement of all parties in the system. In order to make sure that no one party can tamper with these records, each transaction must be verified by other nodes on the network before it’s added to their copy of the ledger (the public record).
In order for this process to work properly, there needs to be some way for everyone involved in making decisions about what gets written into these blocks—otherwise we’d have no way of knowing whether or not someone had altered something after being signed off on (e.g., “Hi!”). This is why blockchains use consensus algorithms like Proof-of-Work (PoW), PoS/Stake etc., which require resources from all parties involved: miners who validate transactions; stakers who stake coins; users who verify transactions via user nodes; etc..
In summary, blockchains are just peer-to-peer networks with a specific consensus algorithms and cryptography.