Marketplaces run Aquarius to store and manage metadata about the [assets](/concepts/terminology/#asset-or-data-asset) available in their marketplace. It provides an HTTP API for interacting with an off-chain database (sometimes called "OceanDB").
Aquarius supports several options for the off-chain database (OceanDB), including MongoDB, Elasticsearch and BigchainDB. One can add support for another off-chain database by creating a new driver similar to the existing OceanDB drivers.
The most basic scenario for a publisher is to provide access to the [assets](/concepts/terminology/#asset-or-data-asset) the publisher owns or manages, but [Brizo can do much more](/concepts/architecture/#brizo).
Brizo supports several options for file storage, including Azure Storage, Amazon S3 and on-premise storage. One can add support for another file storage option by creating a new driver similar to one of the existing Osmosis drivers.
An example marketplace front-end for consumers to explore, download, and publish [assets](/concepts/terminology/#asset-or-data-asset) within the Ocean Protocol network. Implemented using [React](https://reactjs.org/) and [🦑 squid-js](https://github.com/oceanprotocol/squid-js).
Client libraries used by applications (such as Pleuston or Jupyter notebooks) to interact with Ocean components, including Keepers, Aquarius nodes, Brizo nodes, etc.
A [Parity Secret Store](https://wiki.parity.io/Secret-Store): software for distributed key pair generation, distributed key storage, and threshold retrieval. It's used to store [asset](/concepts/terminology/#asset-or-data-asset) access-control keys.