Google Tag Manager is free software from Google that allows you to place different types of code (tags) on your website. A good example of a tag is Google Analytics tracking code, Google Analytics event codes, Google Ads conversion script, and remarketing tags. There are many more types of code that can be added to your website using GTM, including custom codes. Google Tag Manager does not replace Google Analytics or Universal Analytics. Instead, it helps users to easily add Google Analytics tracking codes (tags) to a website, implement GA event code snippets, and define rules when each GA code should fire. Before GTM, GA tracking codes had to be hard-coded, usually by a web developer on each individual page. Having hundreds of events is very difficult when it comes to maintaining/updating them. But Google Tag Manager solves this problem because all your tags are stored in one place – your GTM account.