Final answer:
The 'Tag' property is used to get or set the object that contains data about the control, which is useful for storing additional data without the need for a separate structure.
Step-by-step explanation:
The property used to get or set the object that contains data about the control is referred to as the Tag property.
For example, if you have a control like a button in a C# Windows Forms application and you want to associate some data with it that is not displayed (like an ID or a reference to another object), you can use the Tag property to hold this information.
This allows developers to store additional data directly within a control without needing to create a separate structure for this purpose. So, when you interact with the button or need to retrieve this data, you can quickly access it through the Tag property.