No-fault divorce eliminates the requirement of proving why you want a divorce. Someone used to have to be “at fault”. It used to be that to get a divorce, you had to prove your marriage partner had committed an act that was on a list of justifications for divorce. That meant, some action had to be the reason for the divorce.
Reasons ran the gamut from adultery, spouse abuse, being sentenced to prison for a felony, to flat out insanity.
This made getting a divorce very difficult, and at times very very expensive involving Private Investigators, auditors, psychiatrists, and the like. All states in the US, including D.C., have now passed “no-fault divorce” laws. This means either spouse can file for divorce because they no longer wish to be married, bypassing the court consuming, and sometimes soul-consuming, burden of proving fault.