What is SQL Injection? - Security Term

SQL injection is a type of computer security exploit in which an attacker can gain access to remote database systems. Using a carefully-constructed value for a form field, such as a name or email address, an attacker can fool the application into requesting data from a database which he would otherwise not have access to. SQL injection attacks are similar to XSS attacks in that the attacker is exploiting an application's regular input vectors. Also in common with XSS attacks, SQL injection attacks can be prevented by simple input filtering and validation before the data is passed on for storage or processing.