If you have ever clicked on an article on Facebook, LinkedIn or other sources, you will often see a VERY long URL. The last part of the URL may start with a ?utm at the end of it. These funky codes look intimidating but you don't need to be an engineer to use them! If you work in marketing you should understand what these are and how they are being used.
Here is an example from my favorite daily marketing email Marketing Brew. They append a UTM code onto any URL embedded in their emails. This helps them track the performance of each link-out.
Consider the idea that you may share a piece of site content on Facebook. In the Facebook insights section, you might see that the content was clicked on 45 times. But in reality, someone may have grabbed that article and posted on their personal page, or tweeted it, or texted it to a friend. A UTM code lets you watch the performance of that content from YOUR side across all referral sources.
Another great reason to use UTM codes are for retail performance, which is especially important if you are trying to track conversions in the post iOS14 world. I used it recently to understand how much of my conversion data was disappearing due to new privacy updates (spoiler alert: a LOT). In Shopify, I could look at my sales from the original source UTM code and see that some buyers who came from my Google campaigns were NOT registering as a conversion on my paid search campaign.
UTM codes have limitations. In many cases, you can't see where they go on your page after they arrive. But in a world where we keep losing data points to privacy changes, they remain a constant.
There are a lot of ways you can create a UTM code, from free UTM generators to in-platform generators on Google ads and Facebook ads. I recommend experimenting with how you deploy these tags. Because when it comes to marketing, data is a powerful optimization tool.
Also: I'm fairly lazy at explanations so if this was insufficient here is a much better article on how they work!