What made the 35mm camera important was it's compact size and portability.Barnak's design had the ability for a small area of the light sensitive film to be exposed in capturing the image(the negative)which then could be produced in the dark room.
This is among some of the most important developements in the history of photograhy as camera's could then be taken anywhere,they were also more affordable which allowed anyone to take up photography.
Leitz was the only maker of 35mm camera's for 10 years after the launch of the Leica.Which meant the equipment was still a little too expensive.
In 1936 American company, the Argus company produced a 35mm camera enabling the consumers affordability for the the new technology.Then along came Kodak the biggest name in film and camera equipment,they began making their own 35mm camera which in turn combined with their good reputation and distribution capabilities increased the spread of the 35mm camera.Other notable producers are Olympus,Canon and Pentax in Japan.
Since the 1980's digital camera's have become so sophisticated and widely available.They let the photographer view their images before downloading them to the computer,which is a huge saving not only in time but money and there is no wasted images, if you don't like them just delete them,now you can't do that with a film camera.
Digital photography aslo allows you to print from home the only way you could do that with a film camera was to have a dark room which was another cost and who wants chemicals laying around the house.
Some photographers still prefer the 35mm camera as they offer different effects and possiblities,so they continue to co-exist.
