That allows you to change the view from portrait to landscape layout by simply turning the phone 90 degrees. The accelerometer allows the device of Smartphone to detect the orientation of the device and adapts the content to suit the new orientation. For example, when you rotate your device sideways, the Web browser automatically switches the screen to landscape mode so that you now have a wider viewing space. Similarly, the camera relies on the accelerometer to tell it whether you are taking a picture in portrait or landscape mode.
Now a days there are no dial buttons on the smartphones; all calls are made by using the touchscreen. In order to prevent you from accidentally dialing a number when you talk on the smartphones, proximity sensors to turn off the display when you lift the smartphones to your ear. It detects how close the screen of the phone is to your body. This allows the phone to sense when you have brought the phone up to your ear. At that point, the display turns off in order to save battery.
Ambient light sensors
Basically an ambient light sensor adjusts the display brightness which in turn saves battery power in Smartphone; it saves power by adjusting the brightness of the display based on how much ambient light is present.
It is a type of digital image sensor that uses a novel arrangement of the imaging elements to increase the amount of light captured, increases photon collection and pixel maximization and thereby improves low-light performance to produce better pictures.
It measures the orientation of the device. It can sense motion including vertical and horizontal rotation. There are a lot of practical uses of gyroscope especially in mobile games. Consider a counter-strike like mobile game for an instant. In such games, we are required to move in all directions which also involves rotation around gravity.
Global Positioning System (GPS)
It’s a Navigation tracking, often with a map “picture” in the background, but showing where you have been, and allowing “routes” to be preprogrammed, giving a line you can follow on the screen of Smartphone.
Your smartphone’s uses geo-location information and your Internet connection to retrieve local weather information (current, high, and low temperatures; and current conditions) for various weather data providers. Using the same information you can get the weather forecast for the next several days. Since a barometer isn’t dependent upon a data connection, you could still get “weather change alerts”.