A real-life example of an adapter would be a device that allows you to plug a USB Type-A cable into a USB Type-C port. In a generic sense, an adapter converts an object with a given interface so that it can be used in a context where a different interface is expected.
In software, the Adapter pattern is used to take the interface of an object (the adaptee) and make it compatible with another interface that is expected by a given client. Let's have a look at Figure 8.3 to clarify this idea:
Figure 8.3: Adapter pattern schematic
In Figure 8.3, we can see how the adapter is essentially a wrapper for the adaptee, exposing a different interface. The diagram also highlights the fact that the operations of the adapter can also be a composition of one or more method invocations on the adaptee. From an implementation perspective, the most common technique is...