The document discusses SQL injection and GreenSQL. SQL injection is a code injection technique that allows attackers to gain unauthorized access to databases. GreenSQL is a database firewall that works as a proxy for SQL commands, calculates query risks, and supports different protection modes like IDS, IPS, and learning modes. It fingerprints databases and detects risky queries like stack-based and tautological queries. GreenSQL provides a dashboard to monitor queries and configure whitelist rules and alerts.