The number of megapixels determines the resolution of the images captured with the main camera. A higher megapixel count means that the camera is capable of capturing more details. However, the megapixel count is not the only important element determining the quality of an image.
A BSI (backside illuminated) sensor is a camera image sensor which captures better quality images in poor lighting conditions, and offers better overall sharpness and image quality.
Optical image stabilization uses gyroscopic sensors to detect the vibrations of the camera. The lens adjusts the optical path accordingly, ensuring that any type of motion blur is corrected before the sensor captures the image.
CMOS image sensors are slowly replacing CCD sensors, due to reduced power consumption and better image quality. They can be very compact and cost relatively little to produce.
This allows you to manually set the exposure.
With manual white balance you can choose the most accurate setting and avoid the green, blue or red hue which can occur in auto mode. You can also change the setting for artistic effect.