The Realizes line can be used between any two classifier symbols (class, component, package, and so on), with the meaning that the client (the one at the tail of the arrow) supports at least all of the operations defined in the supplier (the one at the head of the arrow), but with no necessity to support any of the data structure of the supplier (attributes and associations).
Class realizes an interface
The Realizes line is often used to associate a class with the interface it realizes. When a Realizes line is drawn from a class to an interface (class with <<interface>> stereotype), it is shown as a dashed line with a triangular arrowhead. If the interface class is displayed in its shorthand, "lollipop" notation, the Realizes line changes form to be shown as a straight, solid line with no arrowhead.