Relational databases:

The elements in a relational database are organized into tables, with rows and columns. They are the right choice for cases where data integrity is very important (ACID compliant).

Examples: MySQL, Microsoft SQL Server, PostgreSQL, Oracle

Non-relational databases:

They have become an alternative to relational ones as web applications have become more and more complex. They are agnostic in terms of the scheme used, allowing unstructured or semi-structured data to be stored and manipulated.

Examples:

●  Key-Value Stores: Redis, Amazon DynamoDB

●  Wide-Column Stores: Cassandra, Apache HBase

●  Document Stores: MongoDB, Couchbase

●  Graph Databases: Neo4j