The purpose of a SQL database (Structured Query Language) in data management is to create a structured framework for storing, organizing, and retrieving data. SQL databases allow users to define schemas, enforce data integrity, and perform complex queries efficiently. They are instrumental for applications that require transaction management and data consistency, such as financial systems or customer relationship management (CRM). SQL databases support various operations like CRUD (Create, Read, Update, Delete), making them versatile for managing relational data, facilitating analytics and reporting through detailed data insights.