Garnishment is a process by which a person (A) can force another person (B), who owes money to another person (C) to pay A monies those monies owed to C. So, for example, if C owes me money and I know that B owes money to C, I can garnish B's debt to C and get the money instead.
Garnishment is most often used to take money forcibly away from someone who may have put money into a bank account. If C deposits money with the bank (B), then the bank owes C money. If C owes me (A) money, then I can garnish B's debt to C and get the money instead.
In British Columbia, the Court Order Enforcement Act governs how garnishments are executed.
In British Columbia, we often model garnishments as either pre-judgment garnishment and post-judgment garnishment. Pre-judgment garnishment is an extreme (though highly effective if you can get it) tool that a plaintiff obtains before the plaintiff gets a judgment at trial. Post-judgment garnishment is a common tool used to get cash from a defendant who has lost a trial and owes money to the Plaintiff, but still will not pay.