In the context of law, "res judicata" signifies what aspect?

The term "res judicata" refers to the legal principle that a matter that has already been adjudicated by a competent court cannot be relitigated. This principle aims to prevent legal disputes from being decided multiple times, promoting finality and certainty in legal proceedings. When a court makes a final judgment in a case, res judicata ensures that the same parties cannot bring the same dispute before the court again, thereby conserving judicial resources and protecting the integrity of court decisions.

In this context, other options do not align with the essence of res judicata. The option suggesting a new trial can be initiated contradicts the purpose of this principle, as it seeks to prevent repetitive litigation. Similarly, the assertion that appeals are always possible does not hold true in the face of a final decision. Lastly, while the presumption of innocence is a fundamental legal principle in criminal law, it does not relate to the concept of finality in judgments as captured by res judicata. Thus, the correct understanding of this legal doctrine is best represented by the idea that prior decisions cannot be relitigated.