SQL, or Structured Query Language, is a powerful tool for managing and manipulating data in relational databases. Every SQL statement begins with a command keyword. This keyword is crucial because it tells the database management system (DBMS) what operation to execute. Different keywords are used for different tasks. For instance, if you want to retrieve data, you'll use the `SELECT` keyword. If you want to add new data, you'll use `INSERT`. Understanding these keywords is fundamental to writing effective and efficient SQL queries. The keyword acts as the instruction to the database, and the rest of the statement provides the details of the instruction. For example, `SELECT * FROM Customers` tells the database to retrieve all data from the 'Customers' table. The `SELECT` keyword is the command, and `* FROM Customers` specifies the target table and the data to retrieve. This structure is consistent across all SQL commands.