In digital marketing, a parameter refers to a specific piece of data or a reference that is passed to a web page or application to customize the content or track user interaction. Parameters are often used in URLs to track the effectiveness of marketing campaigns, personalize web content, or collect data about user behavior. For example, UTM parameters in URLs enable marketers to identify which campaign or channel drove traffic to their website. Understanding and utilizing parameters are crucial for effective digital analytics, personalization strategies, and campaign tracking.