Key parameters:
utm_source (e.g., Facebook, Google)
utm_medium (e.g., email, CPC)
utm_campaign (e.g., summer_sale)
utm_term (e.g., a specific keyword)
utm_content (e.g., a specific ad creative).
A practical example
A raw URL: www.example.com/signup
With UTMs: www.example.com/signup?utm_source=linkedin&utm_medium=paid_social&utm_campaign=ceo_targeting_q4
When someone clicks this link, Google Analytics records that the visit came from LinkedIn, via paid social, from your Q4 CEO targeting campaign.