Salted hashing is a password storage technique that adds a random value, called a salt, to each password before hashing it. The salt is usually stored with the hash, but it is unique per account, so the same password will not produce the same result across users. This matters because it blocks precomputed cracking methods such as rainbow tables and makes bulk attacks far less efficient.
In a breach, attackers may still try offline cracking if they steal hashed passwords. With salts, they must crack each hash separately, which raises the cost and time needed to recover weak passwords. Good defenses pair salted hashing with a slow password algorithm and a strong work factor, so guessing millions of passwords becomes expensive. In real systems, salted hashing helps reduce the damage of database leaks, but it does not replace multi-factor authentication or the need to reject reused and compromised passwords.