iOS 18.4 introduces new features and settings to enhance device functionality, privacy, and performance.Key settings adjustments are essential to optimize the iPhone or iPad experience.Priority Notifications in iOS 18.4 help reduce distractions by designating high-priority apps.Customizing notification settings ensures focus and timely updates.iOS 18.4 offers expanded default app choices for better device personalization.Safari updates in iOS 18.4 include 'Show Recent Searches' for quicker access to past queries.Apple Intelligence and Siri enhancements in iOS 18.4 provide personalized experiences.The Mail app in iOS 18.4 introduces new customization options for improved usability.Photos app in iOS 18.4 simplifies navigation by allowing removal of unnecessary albums.Sound settings improvements in iOS 18.4 offer better control over audio output.