You may want to track how many people use a specific feature on your website/app.
However, you’re limiting yourself big time. There’s no problem if you want to put the GA tag on all websites and track general information like page views, bounce rate, session duration, referrals, etc. Once an interaction occurs on a site (e.g., pageview), a Javascript snippet sends the corresponding data to Google Analytics. The main way Google Analytics can track these user interactions is with the help of tracking code (also known as GA Javascript code snippet) that must be placed on every page of your website.
