What is the difference between a flat-file database and a relational database?

A flat-file database stores data in a single table, while a relational database uses multiple tables linked by relationships.

A flat-file database is a simple type of database that stores all its data in a single table or list, with fields to represent all parameters. It's a plain text or binary file which usually contains one record per line or physical record. For example, a spreadsheet containing a list of students and their grades could be considered a flat-file database. This type of database is simple to create and manage, but it's not suitable for complex queries or large amounts of data. It also has limitations in terms of data redundancy and data integrity.

On the other hand, a relational database is a more complex type of database that organises data into one or more tables (or "relations") of rows and columns, with a unique key identifying each row. These tables are related to each other based on their data values, and this relationship can be used to access and manage data efficiently. For instance, a school might use a relational database with separate tables for students, courses, and grades, linking students to their respective courses and grades.

Relational databases are more powerful and flexible than flat-file databases. They can handle large amounts of data and complex queries, and they provide robust tools for ensuring data integrity and reducing data redundancy. However, they are also more complex to design and manage, requiring a good understanding of the relational model and SQL (Structured Query Language).

In summary, the main difference between a flat-file database and a relational database lies in their structure and complexity. Flat-file databases are simple and straightforward, but limited in their capabilities. Relational databases, meanwhile, offer greater capabilities and flexibility, but at the cost of increased complexity.