Collaborative divorce is a process, just as litigation is a process. Litigation is the traditional method for divorce. Collaborative divorce has been available in New Jersey since 2014 by statute and practiced in many parts of the world, not just the United States. 
It essentially allows both parties to use their attorneys as negotiators to help them resolve all of their issues and determine their own outcome. No judge is involved. The parties commit to hiring their attorneys for the single purpose of negotiation. The parties also have the benefit of other support professionals such as financial neutrals who collect financial information and make recommendations as to distribution of property, alimony and child support. They couple can also utilize mental health professional to help them focus on productive communication and a parenting plan. There are no hired guns in a collaborative divorce. Moreover, the process is confidential and privileged so the outside world is not privy to any of their affairs, financial or otherwise.
The bottom line is that people can get through a collaborative divorce a lot less expensively than litigation with much more fine-tuned attention to their specific needs and interests and with less adversarial drama and it is done privately in an office setting, not a courtroom or court corridor.