In Hyperledger Fabric, assets are defined as anything that can be given a value. While this could be used to exchange different fiat currencies, an asset could be designed to denote something abstract, such as intellectual property, or something more tangible, such as a shipment of fresh fish.
In Fabric, assets are processed internally as simple key-value pairs, with their state stored on the ledger and modifiable via the chaincode. Assets in Hyperledger can fulfill all the duties performed in Ethereum by ERC-20 and ERC-721 tokens, and beyond. Anything that can be described in a token format can be stored as an asset in Hyperledger Fabric.