If you want to create an object that the user can interact with, then you need to create a control, if you want provide custom behaviour to a form that doesn't necessarily have a user interface, then use a component.

To create a ComboBox with images, you wouldn't go and create a new control, you would derive from the existing ComboBox class and override functionality to provide custom drawing.

Controls are derived from Component. The basic difference though is that components don't have a user interface, for example the OpenFileDialog or ErrorProvider.

Thank you for your answer. It's clear !
So if I want to create a control (actually a ComboBox with images). I am supposed to create a Control and not a component, is that it ?
Do I have any advantage in creating either a component or a control ?

Emphyrio

If you want to create an object that the user can interact with, then you need to create a control, if you want provide custom behaviour to a form that doesn't necessarily have a user interface, then use a component.

To create a ComboBox with images, you wouldn't go and create a new control, you would derive from the existing ComboBox class and override functionality to provide custom drawing.