Hi,

You're welcome.

The lollipop, a small circle on a stick represents an implemented or provided interface. The socket symbol is a semicircle on a stick that can fit around the lollipop. This socket is a dependency, needed or required interface.

Provided and required interfaces define behavior of component.

Component functions are defined using provided interfaces. A required interface defines what functions or services it requires from other components.

http://en.wikipedia.org/wiki/Component_diagram

http://msdn.microsoft.com/en-us/library/dd409393.aspx

http://www.agilemodeling.com/artifacts/componentDiagram.htm