CSS border-width property

Description

CSS border-width is a short hand property of border-top-width, border-right-width, border-bottom-width, and border-left-width properties. It defines the width for all the sides of a block.

border-width : border-top-width border-right-width border-bottom-width border-left-width

mediumDefault: It is the same as border-width: medium medium medium medium;; border-width: medium;
Try it
10px 15px: It is the same as border-width: 10px 15px 10px 15px;; border-width: 10px 15px;
Try it
10px 15px 20px: It is the same as border-width: 10px 15px 20px 15px;; border-width: 10px 15px 20px;
Try it
10px 15px 20px 25px: It is the same as border-width: 10px 15px 20px 25px;; border-width: 10px 15px 20px 25px;
Try it

It applies to all elements

Code

CSS

.parent{
width: 150px;
height: 150px;
background-color: lightgreen;
border:5px solid black;
}

HTML

<div class="parent">
  If the border-style is none then the border-width is of no use.
 </div>