"Before" and "After" Selectors in CSS3

"Before" and "After" Selectors in CSS3

 <style>
p::before
{
content:"I am Narendar:-";
background-color:#FFFF66;
color:red;
font-weight:bold;
}
</style>
<p>this is before selector</p>

<style>
p::after
{
content:"I am Narendar:-";
background-color:#FFFF66;
color:red;
font-weight:bold;
}
</style>

<p>this is after selector</p>

this is before selector

this is after selector