Google Tag Manager is a free tool that allows you to manage and deploy marketing tags (snippets of codes or tracking pixels) on your website without modifying the code itself. GTM becomes very handy when you have lots of tags to manage because every bit of the code is stored in one place. These tags instruct the Google Tag Manager what to do. Examples of common tags within the Google Tag Manager are:
- Google Analytics Universal Tracking Code
- Adwords Remarketing Code
- Adwords Conversion Tracking Code
- Facebook Pixels etc.