Hi @nsvsrk
AEM's JCR (Java Content Repository) is implemented via Apache Jackrabbit Oak, and is considered a type of NoSQL database. It is a hierarchical, document-oriented content repository designed to store structured and unstructured content like web pages, assets, and metadata.
While JCR handles content storage, Solr (or Lucene in embedded setups) is used for full-text search and indexing. AEM uses Oak’s indexing mechanism to determine what content should be indexed. When a query is made (SQL2, XPath, etc.), AEM checks the Oak index definitions to decide whether to query Solr or JCR directly.
Hope this helps,
Daniel