The CSS object-fit property is used to specify how an <img> or <video> should
be resized to fit its container.
This property tells the content to fill the container in a variety of ways; such as "preserve that aspect ratio" or "stretch up and take up as much space as possible".
Look at the following image from Paris, which is 400x300 pixels:
Here we have two images and we want them to fill the width of 50% of the browser window and 100% of the height.
In the following example we do NOT use object-fit, so when we resize the browser window, the aspect ratio of the images will be destroyed: