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 the legal side: GTM should be connected to a consent management platform so that tags which are not strictly necessary fire only once consent has been given. In Austria this obligation follows from section 165 para. 3 TKG 2021; it attaches to storing or reading data on the user's device, regardless of whether personal data is involved. Simply having GTM in place is no substitute for consent control. Which tags count as strictly necessary in a given case is a question of law and should be clarified legally before go-live.