nZEDb is a web-based application (or website) that allows users to search, download, and share news and books. It is a comprehensive content platform that gathers news, books, magazines, and other forms of information from multiple sources around the world. It provides users with an easy-to-use interface and powerful search functions that allow users to quickly find and access the content they are looking for. nZEDb also offers a variety of features, including an RSS feed, automatic and manual downloads, comments, and ratings. Additionally, nZEDb offers an API which allows developers to create their own applications, such as news and book readers, on top of nZEDb.
NZBHydra2 searches other indexers, while nZEDb is an indexer itself.