May be this will help you.
Custom Component means any custom component whether creating it by extending an existing component or creating it from scratch.
Flex allows you to create two type of components MXML and ActionScript components.
If you create components which have some UI elements and those are visible to users (such as ComboBox) these will be called UI Components. It doesn't matter how you create it. On the other hand, any component which doesn't have visual interface (such as HTTPService) will be simply called Component. It cannot be termed as UI Component.
Hope this is clear. If still in doubt, let me know.
Thanks Dajj for the response . Sorry for the confusion ,as i could have mentioned new MXML Component based on container .
Now My question is
" Inside Flex Builder If i create a new MXML Component (a conatiner ) based on Form Container .
Will it be coming as a UIComponnet ??
Please shaer your ideas .
Yes, it will be termed as UI Component simply because it has visual elements.
Let me answer my question .
The UIComponent class is the base class for all visual components, both interactive and noninteractive.
Yes, that's correct...
There seems to be a little confusion here. Think of it this way:
A basic UIComponent by itself is not visible; you can add something you can see to it to make a visual custom component. For example, a ComboBox component is a UIComponent with a ComboBox added to it.
The UIComponent is the lightest weight component available from which you can create other components. I use it as the base for custom components that the user cannot see, like a data manager.
Here we are just talking about the terminology without getting into actual implementation details. The question is which components will be used as UIComponents. The answer is, any component which has UI elements.