Briefly describe the working of Solo or RAFT Hyperledger framework?

Solo and RAFT are two consensus algorithms used in the Hyperledger Fabric framework.

1. Solo: This is a simple consensus mechanism primarily used for development purposes. It involves a single ordering service node, which means there is no actual consensus necessary. The single node orders transactions on a first-come-first-serve basis. However, it is not recommended for production use due to its lack of fault tolerance - if the single node fails, the whole system goes down.

2. RAFT: This is a more complex, production-level consensus mechanism. RAFT stands for Reliable, Replicated, Redundant, and Fault-Tolerant. It involves multiple ordering service nodes that communicate with each other to agree on the order of transactions. If one node fails, the others can continue to operate, providing a level of fault tolerance. RAFT also provides a leader election process, where one node is chosen as the leader to make decisions about the order of transactions, and the other nodes follow.

In both cases, once the order of transactions is determined, they are bundled into blocks and distributed to the peers in the network, who validate and commit the transactions to their individual ledgers.