What is an Elasticsearch index?

An Elasticsearch index is a logical namespace that organizes a collection of documents, each consisting of key-value pairs, within a cluster, allowing for flexible data input without the need for predefined schema, unlike traditional relational databases. Elasticsearch is distinguished by its ability to handle JSON documents, provide advanced search capabilities through its RESTful API, and accommodate dynamic data types, which can be easily adjusted to improve performance. It supports denormalized data storage for faster retrieval and utilizes shards for distributed storage and processing, enhancing scalability. Additionally, Elasticsearch offers inverted indices for text searches, BKD trees for numeric and geolocational data, and dense vectors for semantic search, enabling efficient data analysis and robust search functionalities, including integration with AI-based applications through the Elasticsearch Relevance Engine.