A goal is an action or activity completed by a user on a web resource. You can create goals for specific pages/screens to measure the duration, frequency, or type of user activity. When you configure a goal, you can assign a monetary value to the conversion. After that, each time a website visitor completes the goal, a specific amount is recorded and totaled. The result is available as the Goal Value in your Google Analytics reports. Thus, every action is converted to a dollar value.
For example, you can measure how often leads who complete a specific action make a purchase. If 5% of website subscribers buy products spending $100 on average, your sign-up goal will have a $5 value (5% of $100). It means that each time someone completes the subscription, $5 will be added to your total goal value in GA reports. If 20% of subscribers complete a $100 purchase, the goal value will reach $20. That’s how you can analyze the profitability of different types of activities throughout the conversion funnel.
What does assigning a value to a Google Analytics Goal enable? https://support.google.com/analytics/answer/1012040