What is the term for an element on a Webpage that contains data and procedures for how that item will react when activated

It is an object. And this is because an object has the data and procedures that defines how it is going to react when it is going to be activated. The data is the details about the object, and it explains what the object actually is. And the procedures are the details of the functions that the particular objects can perform. Like for a hospital, data can be mentioning list of medication services they provide, and procedure can be like registering for any medication service, the complete process.

Explanation:

The answer is self explanatory.