As far as I know, there are leaders and verifiers in the solana blockchain. So, what are the roles in the solana chain and what roles do they play?
1 Answer
Broadly speaking there are two roles a given node can occupy: Validator and RPC.
One validator per slot is assigned to be the leader and proposes blocks to the rest of the cluster. The leader is rotated every 4 slots (~1.6 seconds). The rest of the validators verify the blocks produced by the leader and participate in consensus by voting on blocks.
RPC nodes perform many of the same duties as validators except they do not vote on consensus. They simply observe it. They also perform the important job of implementing a set of APIs that external clients can use to understand current state of the network. This could include block or transaction level status among other things.
Solana Docs Terminology may be helpful
