The CONCAT function is a powerful tool for string manipulation in SQL. It allows you to combine multiple strings into a single, larger string. This is crucial for tasks like creating composite keys, generating labels, or formatting data for display. For instance, you might want to combine a customer's first and last name into a single "Full Name" field. The CONCAT function makes this straightforward. Different SQL implementations might use slightly different syntax, but the core concept remains the same. Understanding CONCAT is essential for building robust and flexible SQL queries. It's a fundamental building block for more complex string operations, and its use is widespread in data manipulation tasks.