1. Object-Oriented Database (OODB)

• Stores data as objects, just like in programming (Java, Python, etc.).
• Each object has attributes (data) and methods (functions).
• Good when your app is already object-oriented, so the database can store things in the same way.

2. Graph Database

• Stores data as nodes (things) and edges (relationships between things).
• Best for showing connections and relationships.

3. Document Database

• Stores data as documents (usually in JSON or similar format).
• Each document is flexible → no fixed columns like in traditional databases.
• Good for unstructured or semi-structured data.

Quick Comparison

In simple words:

• Object-Oriented DB = saves things like you do in programming.
• Graph DB = saves things and their relationships like a network map.