If you want to see a 4:3 aspect ratio film- you will have to dig out old black and white video tapes.

For Example:
Charlie Chaplin tapes, we all loved watching as kids. We still enjoy watching them.

The video you are watching now a days is wide screen format.

Q: But what happens if old 4:3 format videos are played on 16:9, widescreen format?
    
Let’s import a 4:3 format video in wide screen and show you.
- The black bars will appear on either sides of the video.

                                                                          Images-aspect ratio 7

Similarly,

Q: What happens if a 16:9 video is played on old TV set with 4:3 aspect ratio?

                                                                        Images-aspect ratio 8

It will have black bars on top and bottom of the video. Or in some cases the video may cut from both sides and picture information would be lost.