SQL Injection is a type of vulnerability in web applications that allows an attacker to execute unauthorized SQL queries on the database by exploiting the application's failure to properly validate user input. The attacker can use this vulnerability to bypass the security measures put in place by the application, allowing them to access or modify sensitive data, or even take control of the entire system. SQL Injection attacks can have severe consequences, including data loss, financial loss, reputational damage, and legal liability. To prevent SQL Injection attacks, developers should properly sanitize and validate all user input, and implement strong security measures, such as input validation, output encoding, parameterized queries, and access controls. Users should also be aware of the risks of SQL Injection attacks and take appropriate measures to protect their data.