People with a collaborating conflict style are both assertive and cooperative. This style is about seeing conflict not as a "you vs. them" game but as an "us" game. Someone with a collaborating conflict style will try to understand the underlying needs and motives of all parties and look for solutions that can optimize the overall wellbeing of everyone involved.
Unlike a compromising conflict style which looks at both sides and tries to meet in the middle, a collaborating conflict style works to explore the real cause of tension and resolve underlying concerns and needs. Sometimes this results in a simple compromise, but other times can unearth entirely new domains of discussion and areas for resolving conflict that allow both parties to win.
A collaborative conflict style is very useful in the area of negotiation, particularly where a long-term relationship is at stake. For instance, if you are negotiating compensation with an employee, if your goal is simply to pay them as little as possible, then you will end up creating hurt feelings which can lead to resentment and a less productive relationship. You might eventually lose that employee altogether. However, if your goal is to explore what is the most fair compensation for the employee and communicate what you are capable of offering given the circumstances, you will ultimately build loyalty and strengthen the long-term viability of that relationship.
People with a collaborative conflict style might sometimes assume that people close to them also have a similar style. When they seek to find an "us" solution, they might become frustrated if the other party is competing or altogether avoiding conflict.