UTM parameters are tags you add to a URL which help you collect extra information in Google Analytics, aggregating valuable data to the data already collected there.

While Tapfiliate is a great resource to track and collect data for your affiliate programs, having a Google Analytics account will help you get other insights regarding the traffic arriving at your website.

The resulting link would be something like:
https://yoursite.com/?utm_source=${affiliate.id}&utm_campaign=${program.title}

This means the different affiliate.id and program.title will appear clearly discriminated in Google Analytics as well.

You can see how to set up UTM tags for your Tapfiliate account here.