Graph Database
A database built for storing and querying relationships between entities. Nodes are entities, edges are relationships. Neo4j is the most popular.
What is Graph Database?
A database built for storing and querying relationships between entities. Nodes are entities, edges are relationships. Neo4j is the most popular.
Graph Database is a intermediate-level concept that sits in the Database Types & Storage area of system design. Engineers reach for it whenever they need to reason about real-world trade-offs in that space — not just for textbook correctness, but because real production systems at companies like Netflix, Amazon, and Google make these decisions every day.
If you want to go deeper than this definition — with diagrams, code, and a quiz to lock it in — work through the "Graph Database" lesson linked below. It walks through the why, the mechanism, the trade-offs, and how the giants actually use it in production.
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Full interactive lesson with diagrams, code examples, real-world references, and a quiz.
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See also
Related glossary terms you might want to look up next.
NoSQL
Databases that don't use traditional table-based relational models. Includes document stores, key-value, graph, and column-family databases.
SQL
Structured Query Language for managing relational databases. Tables, rows, columns, and powerful joins to query related data.
Document Database
A NoSQL database that stores data as flexible JSON-like documents. MongoDB and CouchDB let each document have a different structure.