GTM removes the need for editing the website code over and over again just for adding, removing or editing tags. Instead, one code is placed on every page on the website, which is the GTM container code/tag. This container code literally acts as a container, as it can store and deploy several marketing and analytics tags. If you treat Google Tag Manager tool like a car, then its engine is the container tag and its skin (look and feel) and controls are the user interface. The container tag provides all the functionality needed for GTM tool, to run and deploy tags on your website.