Clickwrap is a legal agreement that obtains binding, active consent from users by having the user take some sort of action to show consent. Common clickwrap methods include a statement such as, "By clicking "Agree," you agree to the following terms," or a checkbox users must click next to a similar statement.
Clickwrap is the recommended method as it gives consent that is legally enforceable in court as a binding. It is considered to be the opposite of browsewrap.