Suggest an editImprove this articleRefine the answer for “How does MongoDB differ from relational databases?”. Your changes go to moderation before they’re published.Approval requiredContentWhat you’re changing🇺🇸EN🇺🇦UAPreviewTitle (EN)Short answer (EN)The main difference is in how data is stored and organized: MongoDB stores flexible BSON documents in collections (relations are often nested inside the document itself), while SQL databases use rigid tables with columns and relations via `JOIN`, and mostly scale vertically. **Key point:** MongoDB fits fast web services, microservices, logging, and frequently changing models with nested objects; SQL databases fit financial systems, strict relations, complex queries, and transactions.Shown above the full answer for quick recall.Answer (EN)ImageThe main difference is in how data is stored and organized. ### 1. Data structure | MongoDB (NoSQL) | Relational (SQL) | |---|---| | Documents in BSON format (JSON-like) | Tables, rows, and columns | | A flexible schema, different structures can live in the same collection | A rigid schema, a table's structure is fixed | ### 2. Relationships | MongoDB | SQL | |---|---| | Relationships are more often nested inside the document | Relationships via `JOIN` between tables | | Suited to denormalized data | Normalization is a key principle | ### 3. Scaling | MongoDB | SQL | |---|---| | Horizontal (sharding is the standard) | More often vertical (scaling the server up) | ### 4. Flexibility | MongoDB | SQL | |---|---| | Easy to change a document's structure | Changing the schema requires migrations | ### 5. When each is better - **MongoDB**, fast web services, microservices, logging, frequently changing models, nested objects - **SQL databases**, financial systems, strict relations, complex queries and transactions **Summary:** MongoDB is document-based and flexible, with an emphasis on scaling and speed. Relational databases are strict, structured, and ideal for complex relationships and transactional integrity.For the reviewerNote to the moderator (optional)Visible only to the moderator. Helps review go faster.