The principle of photography is to focus light with the aid of refraction so as to burn the light catcher medium. Medium that has been burned to the right luminous light size will produce an image identical to the light entering the refracting medium (hereinafter referred to as the lens)
In the era of digital photography where films were not used, the film speed that was originally used developed into Digital ISO.
Photography has now grown into a lifestyle, starting from the advent of the digital age and the development of social media