A more thorough explanation:

Definition: Personation is the act of pretending to be someone else, usually for fraudulent purposes. It is also known as impersonation.

Example: A person who pretends to be a police officer and stops cars on the highway to extort money from drivers is committing personation.

Explanation: In this example, the person is pretending to be a police officer to gain authority and intimidate drivers into giving them money. This is a form of fraud and is illegal. Personation can also occur in other situations, such as when someone pretends to be a doctor or a government official to gain access to sensitive information or resources.