1. Key-Value Store – It has a Big Hash Table of keys & values {Example- Riak, Amazon S3 (Dynamo)}
  2. Document-based Store- It stores documents made up of tagged elements. {Example- CouchDB}
  3. Column-based Store- Each storage block contains data from only one column, {Example- HBase, Cassandra}
  4. Graph-based-A network database that uses edges and nodes to represent and store data. {Example- Neo4J}