In Marketing Cloud Personalization, a Campaign is the primary component that organizes and contains the personalization strategy for a specific channel. It holds the experiences, messages, and business rules you design to tailor interactions for visitors. A campaign defines the target audience (segments), the content or promotions to show (messages within templates), and the conditions under which each experience is delivered.

A. Recipes: Recipes are algorithms that determine which products or content to recommend; they are a component used within a campaign, not the container for it.

B. Templates: Templates are reusable code blocks that define the presentation (HTML/CSS/JS) of a message, but they do not contain the targeting rules or the overall experience.

C. Audiences: Audiences (now called Segments) are groups of users targeted by a campaign, but they are not the component that contains the experiences or messages.

Salesforce Help, Marketing Cloud Personalization, "Web Campaigns," Overview section. This document describes campaigns as the tool to "design and manage all your website personalization experiences."

Salesforce Help, Marketing Cloud Personalization, "Campaigns and Templates," Section: "What is a Campaign?" It defines a campaign as the "who, what, when, where, and why of your personalization efforts."