The Hedera public ledger uses a proof-of-stake consensus mechanism, in which each node’s influence on consensus is proportional to the amount of cryptocurrency it has staked. A transaction is validated and placed into consensus after it is validated by nodes representing an aggregate stake of over two-thirds of the total amount of HBAR currently staked and dedicated to securing the network. Stake is expressed as an amount in HBAR. It is important to ensure that most of the cryptocurrency is actually being staked, so that the network continues to run. This information can be referenced from the latest Hedera whitepaper.
Staking is the process of participating in a proof-of-stake system to validate transactions and earn rewards. When staked, coins are locked but can be unlocked for trading. Staking allows participants (stakeholders) to earn rewards on their holdings, typically in tokens or coins.
Staking rewards distribution can be triggered by several different mechanisms, such as when an account is staked to a different node, when the total number of HBAR staked to an account changes, or when the staked account is auto-renewed.