I'm looking for a word which encapsulates the above concept. An example: when someone knows how to use their phone, but doesn't understand how to take it apart, put it together, etc.
There is a relevant term, but it refers to the object being used, not to the user. In your example, the person is using their phone as a black box. As Wikipedia says,
a black box is a device, system or object which can be viewed in terms of its inputs and outputs [...], without any knowledge of its internal workings.