Elasticsearch is a distributed storage and real-time search engine.
- Distributed storage – you just need to setup and add Elasticsearch nodes, it’ll keep the data distributed on the cluster nodes. The distributed-ness makes data durable and highly-available too.
- Real-time search engine – You can get to query the data the moment it’s been written.
Due to the above 2 attributes you have been listening and reading about Elasticsearch, wherever there’s a discussion of real-time data analysis. It’d not be an overstatement to say technologies like Elasticsearch set the foundation for any efficient and reliable search engine.