A blockchain is a growing list of records, called blocks, that are linked together using cryptography. Each block contains a cryptographic hash of the previous block, a timestamp, and transaction data (generally represented as a Merkle tree).

A blockchain validator is someone who is responsible for verifying transactions on a blockchain. Once transactions are verified, they are added to the distributed ledger.

The word Merkle was derived from the term Merkle Tree which is defined as a way data is organized so that if it were visualized, it would look similar to a tree. Merkle trees are used for efficiently summarizing, verifying, and securing large amounts of data, used in most blockchains. Merkle is a validator/staking service provider for Proof-of-Stake (PoS) blockchains where asset holders/delegators can stake their assets and earn returns while supporting their favorite blockchain by securing the network.

The Proof of Stake (PoS) concept states that a person or entity (like Merkle) can mine or validate block transactions according to how many coins they hold. This means that the more coins owned by a miner, the more mining power they have. This approach employs a faster and less resource intensive consensus mechanism compared to the alternative approach taken by blockchains like Bitcoin also known as Proof of Work (POW) which are highly resource intensive like Electricity.

Validators like Merkle, are special nodes responsible for the provision of infrastructure as well as proposing and validating new blocks and appending them to the blockchain. Hence, together with other validators, they ensure the blockchains security by monitoring its accuracy, establishing validity, guaranteeing availability, and provisioning the infrastructure for it to run on.

Validators earn staking rewards & fees for their work in the form of block rewards & transaction fees. In order to participate in securing the network and to be paid for this service, validators are required to lock up collateral “stake” which can be forfeited (i.e. “slashed”) programmatically if their actions break the programmatic rules that define the blockchain protocol which they secure.

Delegators contribute to the security. The right to validate and add blocks, hence, to secure the validity of the blockchain, is attached to every PoS token. Token holders who do not want to act as a validator, but still want to contribute to the blockchain’s security and earn rewards, can delegate the rights contained in their tokens to a validator of their choice. These token holders are called delegators and can be considered as a validators' customer.

Delegators earn a return on their assets The amount of rewards a delegator can earn through the services of a validator is a function of the validators' total rewards and the ratio between the size of the holder’s own stake and the total stake of the validator. For their services, the validators charge a fee on the token holder’s rewards.