Can You Tell Me That What Are Various Procedure Types In Visual Basic?

There are commonly four types of procedures that are used in visual basic. These are as:
1. event procedures
2. visual basic procedures
3. sub procedures
4. function procedure

Event procedures are those that respond to the events of controls on the form modules. There are various controls (GUI components) that may be added to a form. Each control has some events (like clicking the control with mouse button or pressing a keyboard key etc) to which it reacts.

When one of these control events occurs, the relevant event procedure is called.
The visual basic procedures are used to perform some common tasks. These procedures (like; IIf, format$ etc) are built in, i.e. provided by Microsoft to facilitate the programmer. Programmer does not need to define his own procedure to perform some operations that are handled by these visual basic procedures.

If the programmer wants to perform a task that can not be done by any visual basic procedure available, then the visual basic allows the programmer to define a required procedure. The programmer defined procedure may be a function procedure or a sub procedure.The basic difference between a sub procedure and function procedure is that, a function procedure returns a value to the function caller while sub procedure does not returns any value.