📄️ Publishers and subscribers
A Publisher is simply a node through which certain data enters the network. The data usually originates in an adjacent application that interfaces with the Streamr node, with the goal of delivering that data to Subscribers via the network. Streamr nodes relay the messages to other nodes they are connected to.
📄️ Operators
For instructions on becoming an Operator, check out this guide.
📄️ Delegators
Delegators are DATA token holders who don’t want to be run nodes and be Operators themselves, but would rather earn by delegating their tokens to Operators and sharing the earnings from their work. Delegators are passive liquidity providers for Operators. Delegators are needed when there is an oversupply of technically capable node runners that lack the required DATA tokens in order to stake into Sponsorships. In exchange, they earn a share of the Operator's rewards. Since Operators need to stake tokens to mine Sponsorships, having access to tokens from Delegators helps them to earn more, creating a win-win situation.
📄️ Sponsors
Sponsors pay to secure the operation of a stream. They pay DATA tokens into a smart contract called a Sponsorship. Essentially, the Sponsor says “I want to spend X amount of DATA tokens over a period of time T to improve the security and stability of stream S”. The Sponsorship contract releases the funds over time to Operators who have joined the Sponsorship. It should be noted that a stream can have many Sponsors, and they could be anyone at all, including the Publisher(s), Subscribers, or a third party.