Accomodating

Individuals who negotiate with an accommodating style put great value and emphasis on preserving the relationship. It is a great style when in negotiation with a recurring party say someone whose path you may cross again (Don't burn any bridges).  It is less desirable when you are solely negotiating on a one time basis. 

Avoiding

This style is used by parties who dislike negotiation and tend to avoid it. When trapped in a negotiation, parties will tend to concede swiftly and have little initiative. This can be viewed as diplomatic. The downside is that avoiding parties will not be very likely to obtain a satisfactory result in the negotiation. No offense, but if this is your go to style you may want to re-think career choices.

Collaborating

Collaborating parties like coming to creative solutions during negotiation. This can potentially lead to positive results or transform simple problems into difficult solutions. Either way, parties that prefer a collaborating style make a real effort to understand the issues of the opposing party of the negotiation. If this is your style make sure the simple is not being transformed into the complex.

Competing

Individuals who prefer the competing style of negotiation see negotiation as a game that must be won at any cost. It is an ideal style when dealing with negotiation where lasting relationships are not very important. However, when preservation of the relationship is an issue, the competing style of negotiation is less suited. Is this you or have you had a transaction with someone like this?

Compromising

Parties that value fair and equal deals in negotiation tend to prefer the compromising style. This style tends to get fast results from a negotiation. A pitfall of this style is that concessions often come too fast, without properly discovering the underlying issues. It would  be advisable to dig deeper and know motivation or issues so you know you are not giving too much away.