Filtering data is a fundamental aspect of working with databases. It allows you to extract only the data you need from a larger dataset, rather than retrieving everything. This is essential for tasks like reporting, analysis, and data manipulation. The `WHERE` clause is the primary tool for filtering data in SQL. It follows the `SELECT` statement and specifies the conditions that must be met for a row to be included in the result set. This process is highly flexible, enabling you to filter based on various criteria, including comparisons, logical operators, and more complex expressions. For example, you might want to select only customers who live in a particular city, or products with a price above a certain threshold. This targeted approach significantly improves efficiency and reduces the amount of data processed, leading to faster query execution.