Password complexity and password history are two practices that are being employed by the IT department to establish a new password policy for employees. Password complexity is the requirement that passwords must contain a combination of different types of characters, such as letters, numbers, and symbols. Password complexity makes passwords harder to guess or crack by attackers. Password history is the record of the previous passwords used by a user. Password history prevents users from reusing the same passwords over and over again, which reduces the risk of compromise. Reference : The Official CompTIA IT Fundamentals (ITF+) Study Guide (FC0-U61), page 208.