A nib file, short for NeXT Interface Builder, is a resource file used in iOS and macOS development to store visual interface layouts, configurations, and connections between user interface elements. Nib files are created and edited using Interface Builder, an integrated development environment (IDE) tool provided by Apple for designing user interfaces graphically.
Nib files contain a graphical representation of the user interface layout, including views, controls, windows, and other UI elements arranged visually on a canvas. Developers can customize the appearance and behavior of UI elements, set properties, configure constraints, and establish connections between UI elements and code using Interface Builder’s drag-and-drop interface.
Nib files are stored in a human-readable XML format and have a .xib file extension for individual interface files or a .storyboard file extension for storyboard files containing multiple interface screens. Nib files are compiled into binary format during the build process and loaded dynamically at runtime by the app bundle.
