There is no real diffence. A forced sale is what occurs when you commence a Partition Action, and a Fiduciary is appointed to intercede. If he or she is unable, with the assistance of the Court to effectuate an amicable resolution among all of the owners, then he or she will resport back to the Court to this effect, in which case the Court will Order that the Fiduciary (similar to a Referee in a Foreclosure Action) then sell the property to the highest bidder in a public auction.
As you mentioned, a Partition Action is an option. A Partition Action may be brought by a tenant in common. If you own the property as a tenant in common with the other two owners, then you can ask the court to dissolve the ownership. The court may force a sale to a third party, whereupon the proceeds will be divided as per the court's order. It may also allow one or more owners to buy out the other owner(s).
Note: This response is for general informational purposes only. No attorney-client relationship is created. No responsiblity shall be taken by the submitting attorney for any individuals acting pursuant to any information contained herein.
Your only real option if your co owners will not buy you out is a action to partition the property. In a partition action, the court orders the sale of the property by auction with an allocation on an equitable basis. If no deal is made, everyone loses unless someone has the money to bid in the property in the auction.
My answer to your question is for general purposes only and does not establish an attorney-client relationship,