Elasticsearch and Apache Solr are both open source search engines.
Elasticsearch is a distributed search engine based on Apache Lucene and is built for scalability, resilience, and ease of use. It is a NoSQL database that stores data in a JSON document format and supports powerful search capabilities. It is also highly extensible and provides a RESTful API for easy integration with other applications.
Apache Solr is an open source search server based on the Lucene Java search library. It is capable of handling large volumes of text-centric data and provides powerful search capabilities. It can be used to index and search data from any source, including databases, web pages, and file systems. It also provides rich document processing capabilities such as text analysis, faceting, and highlighting.
An example of a use case for Elasticsearch would be a large-scale web application that needs to quickly search through millions of records. Elasticsearch would be able to quickly index and search through the data with its powerful search capabilities.
An example of a use case for Apache Solr would be a content management system that needs to quickly search through large volumes of text-centric data. Apache Solr would be able to quickly index and search through the data with its powerful search capabilities and rich document processing capabilities.