Wat's the role of this instruction?

    videoFileReader = imaq.VideoDevice('winvideo', 1, 'MJPG_640x480','ROI',[1 1 640 480]);

• What does ('winvideo', 1, 'MJPG_640x480','ROI',[1 1 640 480]) mean?
• What does this instruction do?

Answer 1

[the cyclist]

Here is a link to the documentation for this command.

Answer 2

[Image Analyst]

Those are the arguments that you use to set up an object that is basically your video camera. You can change them to set up different physical cameras, camera resolutions, frame rates, etc.