Final answer:
The Sitecore Experience Platform (XP) is the crucial feature enabling WCM in Sitecore, providing integrated content management and personalization capabilities.
Step-by-step explanation:
The feature that makes Web Content Management (WCM) possible in Sitecore is known as the Sitecore Experience Platform (XP). Sitecore XP integrates digital marketing with content management, allowing marketers to deliver personalized content in real-time and across different channels. Core to Sitecore's ability to manage content effectively is its Item Management system, which stores content as items that can be reused and repurposed across various sections of the website, facilitating efficient content handling and updates. Another significant feature is the Experience Editor, a WYSIWYG editing tool that enables users to edit content directly in the context of a website so that they can see exactly what changes will look like live.