Blockchain

An immutable, digital ledger that facilitates the process of recording transactions and tracking assets in a network; it is updated and shared across many computers in a network.

Cryptocurrency

A currency that is digital & decentralized.

Crypto removes the need for a trusted authority or "middle-man" to certify the validity of a transaction.

Can be used to buy & sell goods or as a long-term store of value.

Nodes/Miners

The “boots on the ground” of blockchain networks. They are the physical computer hardware that runs their respective platform’s blockchain software.  Nodes serve several critical functions:

1. They vote on and validate blocks of transactions
2. They communicate with other nodes to agree on the state of the blockchain
3. They store the history (state) of the blockchain as a universal source of truth
4. They are the endpoints of the network that enable users to access and interact with applications built on the network.

Validators

Validators are the miners of a proof-of-stake network. Like miners, the validators’ role is to collect transactions into blocks to add to the blockchain. For adding valid blocks, validators are rewarded in proportion to the amount of currency they post (“stake”) as collateral.

Block

A block is like a folder that contains “files”. The contents of this folder are the transactions that occur over a given time interval (hashed to a cryptographic digest). Each block contains a reference linking it to the previous block — hence the term “blockchain”.

Blocks are added by the miners or validators on a cryptonetwork according to a consensus protocol; they check:

• to ensure balances are not spent twice;
• that each digital signature matches the public key of the message; and
• that the included reference matches the hash of the previously-added block.