In this highly connected world, your content can be stored in different places. Listed below are the different sources Somersoft has worked with.
MySQL/MariaDB
Popular database server and its forked competitor.
PostgreSQL
Rising popular database server.
SQLite
A file based database server.
Solr
Search engine based upon Apache Lucene project.
Elasticsearch
Search engine also based upon Apache Lucene project, but different to Solr.
Opensearch
Search engine forked from Elasticsearch.
SOAP
Early open standard for passing data between client and source.
JSON
Rising open standard for passing data between client and source.
GraphQL
Rising open standard from Facebook for passing data between client and source.
Files
Content can also be stored in files in many different formats from the older CSV through to the newer YAML.