You can change it back by going to Settings ... you can also use an option in the Accessibility settings to turn off Silent ...

Control Center was once a convenient place to quickly access controls such as playback volume and Airplane mode, but under ...

Push this switch so that the orange indicator is revealed. This puts your iPhone in silent mode, meaning texts and voice calls will not ring out loud. Note that enabling silent mode while watching ...

Customize the iPhone Action ... action to change the time that the function of the Action Button changes. You can replace the ...