Aspect ratio refers to the dimensions of a screen in a ratio of width:height.

Over the history of screened media many aspect ratios have been used. Most modern TVs are a 16:9 ratio, whilst older screens tended to be 4:3 which gave a much more “square” screen compared to the wide rectangular shapes used today.

The history of aspect ratios used in cinema is more complex, in the early days of flmmaking many directors chose their own aspect ratio, ranging from perfectly square to extremely wide. Although as films became more standersied a few aspect ratios became the norm, these differed from via region.

Aspect ratio becomes an important issue when displaying media on a screen of a different aspect ratio than the one it was originally intended for. The options are to either have “blank space” where the original image wouldnt have filled on a different screen, having the image cropped so that it fills the screen, orstreching the image.

All 3 have advantages and disadvantages. With the first the entire image is displayed, and it has the correct dimensions, but depending on the screen could have more “spare room” than actual media. The second fills the screen and leaves proportions of the image intact, but can cut off the top or sides of the screen, which could severely change the media. The third option fills the entire screen, and has the entire image, but stretchs it vertically or horinzonally, distorting the image.

Personally I prefer the first option, I will always prefer to experience media as the original artist intended and compromise with a smaller screen size than crop or distort the image.