Both enforced through the implicit threat of violence... What happens if I ignore a court summons? Eventually the cops will find me and wrestle me into handcuffs. And if I try to resist the tow truck driver taking my car, guess what they'll do? They'll call the cops. Or they'll put a lien against my property, which if I refuse to pay, will eventually culminate in me being wrestled out of the building.

And how exactly do you think people are kept in jails? If there were no implicit threat of violence, I'd just walk out of a jail. In many jails this would be possible, but when you do they'll send men to wrestle you into handcuffs and bring you to a jail with stronger security. And of course, they'd never have gotten me into the first jail at all, if not for their threats of violence.