Res judicata

 The concept of "res judicata" in civil law refers to the principle that a matter that has already been decided by a court of competent jurisdiction cannot be re-litigated or re-opened. 

The principle of res judicata is based on the idea of finality of judgments and the need to conserve judicial resources and prevent repetitive lawsuits.

Under res judicata, a final judgment on the merits in a previous suit between the same parties is conclusive as to the rights and liabilities of the parties in the subsequent suit. The principle applies to both the actual matters that were put in issue as well as to all matters that could have been put in issue in the previous suit.

The purpose of res judicata is to ensure that there is no multiplicity of proceedings, prevent vexatious litigation and ensure that parties are not harassed by repeated lawsuits on the same issue. It promotes judicial economy, prevents abuse of the legal system and provides certainty to the parties in litigation.

In order for the principle of res judicata to apply, certain conditions must be satisfied, including that the previous suit must have been between the same parties, the subject matter must be the same, and the relief sought must be the same. Additionally, the previous suit must have been heard and decided by a court of competent jurisdiction and the judgment must have become final and binding on the parties.

In conclusion, the concept of res judicata is a fundamental principle of civil law that ensures that a matter that has already been decided cannot be re-litigated. The principle serves to promote judicial economy and prevent the abuse of the legal system, and is an important tool for ensuring the efficient administration of justice.