A database is generally used for storing related, structured data, with well defined data formats, in an efficient manner for insert, update and/or retrieval (depending on application).
On the other hand, a file system is a more unstructured data store for storing arbitrary, probably unrelated data. The file system is more general, and databases are built on top of the general data storage services provided by file systems. [Quora]
The file system is useful if you are looking for a particular file, as operating systems maintain a sort of index. However, the contents of a txt file won’t be indexed, which is one of the main advantages of a database.
For very complex operations, the filesystem is likely to be very slow.
Main RDBMS advantages:
- Tables are related to each other
- SQL query/data processing language
- Transaction processing addition to SQL (Transact-SQL)
- Server-client implementation with server-side objects like stored procedures, functions, triggers, views, etc.
Advantage of the File System over Data base Management System is:
When handling small data sets with arbitrary, probably unrelated data, file is more efficient than database. For simple operations, read, write, file operations are faster and simple.
You can find n number of difference over internet.