Relational & Non-Relational Databases

These are also called SQL databases.
These are used to store structured data.
Relational Databases stores data in rows and columns.
Relational Databases can be accessed using SQL (Structured Query language), as the language for querying and maintaining the database.
These support ACID (Atomicity, Consistency, Isolation, Durability) transactions, as the integrity of data is very important.
Relational Databases are mainly used for OLTP (Online transaction processing), which includes business transactional processing using real-time data.
For example, Database to hold transactions from ATM.

These types of databases are also called NoSQL databases OR “Not only SQL” databases.
These databases store a large amount of unstructured data.
These don’t use relational models and schema.
These databases are designed to run on large clusters.
Non-Relational Databases use JSON, XML, or Key-value pairs.
These can be column-based, document-based, or graph-based.
These also have a flexible schema, so it can be a row-based, column-based, or follow document approach.
Most NoSQL databases support data replication, storing multiple copies of data across the cluster or data centers to ensure high availability and disaster recovery.
Non-Relational Databases are used for BigData and real-time web applications, where a huge amount of data is being delivered.