A .sql file is a plain text file containing SQL (Structured Query Language) code. SQL is a standard programming language used for managing and manipulating data held in relational database management systems (RDBMS). These files typically contain a series of SQL statements, which can include commands for creating, reading, updating, and deleting (CRUD) data within a database. They can also contain commands for defining the database schema, such as creating tables, defining relationships between tables, and setting constraints on data integrity. SQL files are often used to execute a batch of operations against a database, such as initializing a database with a predefined structure and data, applying schema changes, or running complex queries. They are essential for database administration, application development, and data analysis, providing a standardized way to interact with and manage relational databases. The files can be executed by various database management systems like MySQL, PostgreSQL, Oracle, SQL Server, and SQLite. The specific SQL dialect used within the file might vary depending on the target database system, but the core SQL syntax remains largely consistent.