Not all HTML tags are of the same structure. While most elements require an opening tag, a closing tag, and contents, some elements - known as void elements - only require an opening tag as they themselves do not contain any elements. This topic explains and demonstrates the proper usage of void elements in HTML
A void element cannot have any content but may have attributes. Void elements are self-closing, so they must not have a closing tag.
In HTML5, the following elements are void:
area
base
br
col
embed
hr
img
input
keygen
link
meta
param
source
track
wbr