What is Aspect Ratio? Does it Matter?

Long, long ago, in the before time, there was the 35mm camera. The 35mm camera produced images with an aspect ratio of 4 x 6 or 6 x 4. And so it was, and so it continued to be, until someone invented the digital camera and decided that the standard aspect ratio was going to change. So, what is aspect ratio and why do you need to worry about it?

Read on to find out.