Visual Basic 6 is event-driven programming

Visual Basic lets you build a complete and functional Windows application by dropping a bunch of controls on a form and writing some code that executes when something happens to those controls or to the form itself. For instance, you can write code that executes when a form loads or unloads or when the user resizes it. Likewise, you can write code that executes when the user clicks on a control or types while the control has the input focus.

This programming paradigm is also known as event-driven programming because your application is made up of several event procedures executed in an order that's dependent on what happens at run time. The order of execution can't, in general, be foreseen when the program is under construction. This programming model contrasts with the procedural approach, which was dominant in the old days.