A data file is a physical file that stores data on a computer. It is usually in a specific format, such as a text file, binary file, or spreadsheet. A database is an organized collection of related data stored in a computer system. It is typically structured in tables, records, and fields and is used to store and manage data. MSSQL is a relational database management system (RDBMS) developed by Microsoft for use with their SQL Server product. It is used to store, manipulate, and query data in a database.