The simplest way to add an icon to your HTML page, is with an icon library, such as Font Awesome.
Add the name of the specified icon class to any inline HTML element (like <i> or
<span>).
All the icons in the icon libraries below, are scalable vectors that can be customized with CSS (size, color, shadow, etc.)
To use the Font Awesome icons, add the following line inside the <head> section of your HTML page:
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css">
To use the Bootstrap glyphicons, add the following line inside the <head> section of your HTML page:
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
To use the Google icons, add the following line inside the <head> section of your HTML page:
<link rel="stylesheet" href="https://fonts.googleapis.com/icon?family=Material+Icons">