There are three ways the component symbol can be used.
1) Rectangle with the component stereotype (the text <<component>>). The component stereotype is usually used above the component name to avoid confusing the shape with a class icon.
2) Rectangle with the component icon in the top right corner and the name of the component.
3) Rectangle with the component icon and the component stereotype.
Provided Interface and the Required Interface
Interfaces in component diagrams show how components are wired together and interact with each other. The assembly connector allows linking the component’s required interface (represented with a semi-circle and a solid line) with the provided interface (represented with a circle and solid line) of another component. This shows that one component is providing the service that the other is requiring.
Port (represented by the small square at the end of a required interface or provided interface) is used when the component delegates the interfaces to an internal class.
Although you can show more detail about the relationship between two components using the ball-and-socket notation (provided interface and required interface), you can just as well use a dependency arrow to show the relationship between two components.