The QFile class provides an interface for reading from and writing to files.| doc.qt.io
The QSettings class provides persistent platform-independent application settings.| doc.qt.io
The QMetaType class manages named types in the meta-object system.| doc.qt.io
The QDataStream class provides serialization of binary data to a QIODevice.| doc.qt.io
The QVariant class acts like a union for the most common Qt data types.| doc.qt.io