Google Analytics provides all the tracking that you need on your website. However, there is certain information like, links/button clicked by individuals, how long they have seen any video, who have submitted the form cannot be tracked by Google Analytics. To track this data you need to hire developers knowing JavaScript. This is where you need Google Tag Manager as it manages Google Analytics and also enables the tracking codes through it. Continue reading... https://www.xenia-consulting.com/top-10-reasons-why-you-should-use-google-tag-manager/