A UTM code (or parameter) is a simple code that you can attach to a custom URL to track a source, medium, and campaign name. This enables Google Analytics to tell you where searchers came from as well as what campaign directed them to you. You can also add this into a marketing automation platform to track your campaigns.
UTM codes allow you to measure your success for marketing tactics.
An example of a UTM is:
https://www.newearthmarketing.com/What-is-a-utm-code?utm_campaign=blogging &utm_medium=social&utm_source=linkedin
Google support and form for url builder
Its also sometimes handy to use a url shortener too.
