Final answer:
The key difference between databases and a file-based approach is that databases provide structured and scalable management of complex data relationships with data integrity, whereas file-based systems consist of separate files without advanced querying capabilities.
Step-by-step explanation:
A key difference between databases and a file-based approach to storing data involves how data is organized, accessed, and managed. In a file-based system, data is stored in separate files, with a structure that can vary from one file to another. On the other hand, a database is designed to hold more complex data relationships and enables one to query and manipulate data in sophisticated ways, often through a Database Management System (DBMS). Specifically, databases allow for data integrity, avoid data redundancy, and provide concurrent user accessibility, which results in better maintainability and scalability compared to a file-based system.