What are the differences between traditional structured databases and more flexible NoSQL storage systems?

Structured traditional databases (relational):

• Use tables with a fixed schema (rows and columns).
• Support SQL for queries.
• Provide transactions with ACID properties (atomicity, consistency, isolation, durability).
• Well-suited for data with a clearly defined structure.

Non-relational databases (NoSQL):

• More flexible schemas or their absence (documents, key-value, graphs, etc.).
• Often scale horizontally.
• May sacrifice some ACID properties for performance and scalability (e.g., eventual consistency).
• Suitable for large volumes of heterogeneous data with rapidly changing structures.

Thus, the choice depends on requirements for data structure, scalability, and consistency.