A more thorough explanation:

Definition: Preventive custody is a type of custody that is intended to prevent further dangerous or criminal behavior. It involves the care and control of a person for inspection, preservation, or security.

Example: If a person is suspected of planning a terrorist attack, they may be placed in preventive custody to prevent them from carrying out the attack.

This example illustrates how preventive custody is used to prevent dangerous behavior. By placing the person in custody, they are unable to carry out their plans and potentially harm others.