What is Google Tag Manager?
Google Tag Manager is a free tool that lets you implement and configure tags on your website or mobile app, without changing the source code. You implement GTM through a tag with which you implement all other tags. The tag configuration is handled in a user-friendly GUI (graphical user interface), making code changes easy to deploy.
With GTM you can implement frontend changes across many domains and languages in seconds without the need of a developer. Managing and configuring tags became a lot easier, which made it a new standard for Marketers and Analytics professionals.
Typical use-cases are Google Analytics implementations and the integration with retargeting services like Facebook, Google Ads etc.
GTM is also great for tracking user behavior on a website.
You can set up event tracking on a page and track clicks, shopping cart actions or scrolling behavior to optimize your content.
GTM is the most-widely used tag management system, though there are other competitors, like Adobe Launch and Tealium iQ.
If you want to learn how to use Google Tag Manager, read my guide on how to implement a Google Analytics setup with GTM. Afterwards learn how to set up event tracking with GTM.
GTM overview and capabilities
Have a look at the official introductory overview by Google:
Benefits of Google Tag Manager
The main benefits of GTM are the fast and flexible implementation of tags to a website and the scalable data management between all tags. This saves time, resources and budget.
Have a look at the benefits of Google Tag Manager for a more detailed explanation.
You can start using Google Tag Manager for free by visiting tagmanager.google.com
Read Google's quick start guide.