Google Tag Manager gives the facility to put Custom HTML Tag , Google analytics Tag , Image Tag etc. Here i explained this video using Google blog illustration. it is a free tool that makes it easy for marketers to add and update website tags, like conversion tracking, site analytics, re marketing audience and more. All that with just a few clicks and without changing your website code. Google Tag Manager lets you import and merge containers to your existing containers uploading a simple file. To implement Google Tag Manager, copy the code provided in Tag Manager and Paste this snippet into your website template page so that it appears immediately after the opening body tag.