Many ad networks, or platforms like Google Analytics, require you to insert small pieces of code into your site’s header or footer code.
While you can manually edit your site’s PHP header and/or footer files, we do NOT recommend this unless you are well-versed in coding PHP. This is because the site PHP is like your blog’s skeleton—break something in one spot, and it can break the whole site! Instead, we recommend anyone needing to insert code into their header or footer code use this plugin. It makes it really easy to insert the scripts you need, without touching our actual theme files!
Also, please note that if you’re using Google Analytics, you might find it easier to use the Google Analytics for WordPress by Monster Insights plugin. This plugin allows you to easily insert your Google Analytics ID via the plugin interface, and also supplies you with your Google Analytics stats right on your WordPress dashboard!