Google Tag Manager (GTM)
Google Tag Manager (GTM) is a free tag management system that lets you manage marketing and tracking codes (tags) from one central interface instead of adding each one to the source code by hand. Triggers and variables control when each tag fires, which cuts the workload for development teams every time a new tracking requirement comes up.
In practice
In practice, the people responsible for analytics maintain things like GA4 configuration tags, Google Ads conversion tags or third-party tags in GTM, without developers having to touch the website each time. The built-in preview and debug mode lets you test new container versions before publishing them. Important for GDPR compliance: GTM has to be connected to a consent management platform so that tags fire only once the relevant consent has been given – simply having GTM in place is no substitute for consent control.