Easy step with nib file to make iOS app ui without storyboard in Xcode 8
XIB stands for the XML Interface Builder.
Interface Builder is a software application which allows you to develop Graphical User Interface with the help of Cocoa and carbon. The generated files are either stored as NIB or XIB files. These files are copied into the app bundle and loaded at run time to provide the user interface for the application. XIB files were introduced in 2007 with Leopard (Xcode 3.0).
XIB files is not a package, but a self-contained XML file. Xcode will convert the XIB file into deploy-able NIB when the project is built and will include the NIB file in the finished application.