Consensus mechanism
A set of rules by which participants in a decentralized network agree on which version of the blockchain is valid (for example, Proof-of-Work or Proof-of-Stake).
See also
Halving
A programmed event in the Bitcoin network (and some other coins) where the block reward paid to miners is cut in half. It happens roughly once every four years.
Hard fork
A backwards-incompatible change to a blockchain's protocol that splits the network into an old and a new chain (example: the split of Bitcoin and Bitcoin Cash).
Soft fork
A backwards-compatible update to a protocol's rules, where old nodes can continue operating on the upgraded network without being forced to update.
Proof-of-Work (PoW)
A consensus mechanism in which miners prove they performed computational work in order to add a new block. Used by Bitcoin, among others; it requires significant energy.
Proof-of-Stake (PoS)
A consensus mechanism in which the right to validate blocks goes to participants who have locked up (staked) their cryptocurrency as collateral. It is more energy-efficient than Proof-of-Work.
ERC-20
A technical token standard on the Ethereum network that defines common rules for creating fungible tokens. The vast majority of tokens on Ethereum are issued under this standard.