Step 1: Understanding the Concept:
The question asks for the technical term for the prologue or introduction of a play in the tradition of Sanskrit drama.
Step 2: Detailed Explanation:
In classical Sanskrit theatre, the Prastavana (also spelled Prasthaavana) is the introductory part of the play that comes after the initial benediction (Nandi). In the Prastavana, the Sutradhara (Stage Manager) enters and, often in dialogue with an actress (Nati) or another character, introduces the name of the playwright, the title of the play, and hints at the plot or the main theme. It serves to set the scene and capture the audience's attention.
Step 3: Final Answer:
The introductory sequence that states the substance of a play is called the Prastavana.