This is a very broad question. In short each protocol was built with rules to potentially address a particular objective or business use case challenge.
So the answer to your question can be narrowed by differentiating the purpose for each protocol is built.
Blockchain protocol solves decentralized ledger
Ethereum protocol solves decentralized ledger ,enable decentralized applications and smart contracts
Ripple protocol solves not only decentralized ledger, smart contracts but also addresses speed and cheaper transactions
Hyperledger Fabric solves providing restricted access to decentralized ledger.
R3's corda solves decentralized ledger for financial sector with no need for mining
Therefore each protocol has logic and rules built trying to solve the primary objective it chose. However the underlying concept is still the blockchain for each of the protocols.
Hope this answers your question at high level.
