A blockchain is a type of distributed ledger. But new distributed ledgers are emerging. These are databases where control over the data’s evolution is shared between entities. Here’s a handy cheatsheet.
When people ask, “What is Hyperledger?”, the answer I give is usually “Do you mean the project called Hyperledger run by The Linux Foundation, or do you mean one of the ledger technologies incubated by that project which used to be confusingly called Hyperledger Fabric?”. The first is a group of people, the second other is a bunch of code.