A Divorce and a Dissolution are two different ways to legally terminate a marriage. Both result in the legal end to a marriage.
A Dissolution is essentially an agreement reached between the parties, after full and complete disclosure of all assets and liabilities of both parties. You can think of a dissolution as an uncontested divorce, and it typically involves some negotiation between the parties to reach an agreement that is acceptable to both spouses.
Divorce is a more formal legal process than dissolution. In cases where one or both parties want the court to invoke its jurisdiction to hear the case and issue orders, or when financial documents and/or employment information needs to be obtained by subpoena, a dissolution may not be possible or in the parties' best interest. While most divorce cases are settled prior to trial, there is still the possibility that a final evidentiary hearing will be necessary.
Generally, dissolutions tend to be less expensive and are typically resolved in a shorter amount of time than divorces.