Smartphones use multiple sensors to detect orientation:

• Gyroscope: Measures rotation and twist
• Magnetometer: Determines direction like a compass
• Accelerometer: Detects movement and gravitational forces

This sensor combination enables accurate device positioning, allowing apps to automatically adjust their layouts. Common applications include:

• Photo galleries expanding images to full width in landscape
• Video players maximizing screen space for content
• Maps rotating to match the user's orientation
• Games adapting controls based on device position

While automatic orientation changes can enhance the viewing experience, they should be purposeful and match user behavior. For example, video apps typically switch to landscape for fullscreen playback but maintain portrait mode for browsing.