Considering the fact that you are new to the world of blockchains, I would like to familiarize you with the concept of blockchain before answering this question.
As per definition, blockchain is nothing but a distributed and decentralized digital ledger which records transactions across a global network of computers where the information is highly secure. As the name suggests, blockchain is a linear chain of blocks that holds information of transactions taking place over the web. Every block contains data in the form of coding that is organized in a chronological manner.
This concept is leveraged by several projects. You might be familiar with some of them. These include bitcoin, ethereum, and ripple amongst others.
Hyperledger is one such project that leverages the blockchain technology for enabling open industrial blockchain development. With industrial developments in the limelight, it can be assumed that several companies use Hyperledger to develop blockchain systems as per their requirements. As a matter of fact, all companies leverage Hyperledger but covertly manage and maintain their own versions.
Hyperledger Fabric is the Hyperledger specification which is maintained and managed by IBM.