.NET Building Blocks: Custom User Controls in Practice

ccording to MSDN's documentation (specifically Varieties of Custom Controls) there are three types of custom controls. The names Microsoft has chosen to use for these three in the documentation are confusing: composite control, extended control, and custom control. The inclusion of "custom control" as a type means you can never be sure which type is being referred to by the generic term "custom control." The following discussion substitutes "raw control" for the third type of custom control.

Furthermore, this list of three custom controls should really be a list of four custom controls: composite control, extended user control, extended system control, and raw control, because although there's no conceptual difference between extending a user control and extending a system control, there is a practical difference, as you will see shortly.