Cocoa bindings
A technology central to macOS development, Cocoa bindings is a feature that allows you to establish connections between the AppKit classes that we use to provide an app with standardized UI elements, and your model object's (or objects') data. There are other ways to do this, but at the moment we will concentrate on bindings, since they can save us large amounts of what is generally referred to as glue code, the stuff that tells your data model what the user has done, and tells your user interface what change the model has made to its data.
Using Cocoa bindings, we can keep the data and the UI synchronized at all times. And the amazing thing is, we do it without a single line of code.
If you already have a fair amount of experience in programming for OS X/macOS, you will probably have some idea of how to use Cocoa bindings, but we will nevertheless run quickly through how to connect your UI in Interface Builder with your data model.
Since we have the PeopleWatcher app lying around...
