What is background-size CSS?

The background-size CSS property sets the size of the element's background image. The image can be left to its natural size, stretched, or constrained to fit the available space.

How to make a picture fit on a screen in CSS?

If you give a width of 100px or 100%, the height will be definitely 100px or 100% because the browser calculated based on the aspect ratio. You can make your image fit on the screen by using the cover value in the CSS background-size property. It also fits the portrait image, but the image looks bigger. So you use the landscape image.

What is the difference between first and second background image?

The first background is fine and fits to the screen width & height but the second one is not scaling to fit the screen height. Kindly help me with this. Its CSS code is given below.

How to scale an image up in the background?

On the other end of the spectrum, you can scale an image up in the background. Here we scale a 32x32 pixel favicon to 300x300 pixels: As you can see, the CSS is actually essentially identical, save the name of the image file. Besides values, the background-size CSS property offers two special size values, contain and cover.