What do the Aspect Ratio settings on Channels and Content mean?

In both the content editor and the channel editor, there is an option called Aspect Ratio that controls how your content is displayed when it doesn't match exactly the size of the display or the container it is in (for multi-zone channels).

There are three options for Aspect Ration in Appspace:

• Uniform is our recommended option as it maintains the original aspect ratio of your content and prevents it from overflowing the screen, though it will cause letter-boxing or column-boxing depending on which direction it is off in.
• Stretch / Fill is an option that will ignore the original aspect ratio of the piece of content uploaded and stretch or compress your content until it fills all corners of the screen, causing distortion.
• Uniform Fill will respect the original aspect ratio, but still force the piece to scale up to fill the window, causing pieces of content to be cropped off if they overflow the bounds.