If you have seen web design projects that seek to emulate the look and functionality of desktop environments for operating systems, you may have noticed that the option of setting a wallpaper or background image stretches out to fill the viewport; in many cases, this is accomplished with responsive design so that it fits various screen sizes, and it is a matter of using object-fit CSS properties.
The CSS object-fit property is used to code how images or videos need to be resized for the purpose of fitting within specific containers. This property instructs the media to fill up the container in ways that will either stretch out or stick to a determined aspect ratio.
As we will see, when combined with a source, and when used with a video, object-fit can lead to some rather remarkable effects. This property can be used in conjunction with either the img or video tag, and it accepts three values: "cover", "contain" and "stretch". Let's say the media in question is a photograph of a city skyline; you can make it work when combined with an object-fit: cover property.
The image is resized to its container, which is specified as a 100% width and 100% height. When the object-fit is set to cover, the background image is scaled and overlapped so that it appears to fill the viewport. In most cases, this can result in a much more pleasing and realistic display. However, if it doesn't fit properly, you can easily add overflow: visible to the image and specify a particular height for the object-fit: cover option.
You may have also noticed the background image of the website, and that it stretches out to fill the entire width of the browser. To make it work, you have to use the object-fit: contain option. This property instructs the media to be contained within the specified container. So instead of stretching, it will stick to the sides of the screen, leaving the rest of the screen empty. Now, to use this to its maximum advantage, we can apply a background color on the body of the document. For more information click here https://i.redd.it/wzjosm4dh8o71.jpg.