wide angle- It is the angle used to cover a huge area during photo-shoot. When the focal length is decreases the angle increases of the camera and thus it can capture a huge area. The wide-angle camera used in smartphone has a fixed minimum (less than 33 mm) focal length. As focal length decreases the wide-angle increases. When wide angle increases the covering area by the camera increases.  

This camera is useful when user have to take a landscape photo as it covers more area.

Another term “Ultra-wide angle” means more wider angle e.g., 114, 120 Degree angle.