Ace the Google Analytics IQ Test 2025 – Unleash Your Data Superpowers!

Google Analytics uses specific dimensions to categorize how visitors arrive at a website. The default traffic source dimensions that Google Analytics reports for each website visitor are Source and Medium.

The "Source" dimension identifies where the traffic originates from, such as a search engine (like Google) or a specific website (like a referral site). The "Medium" dimension, on the other hand, describes the general category of the source, such as organic search, paid search, or referral.

Combining these two dimensions allows marketers and website owners to understand not only where their traffic comes from but also how it arrived — whether it was through organic search, a paid advertisement, or another channel. This information is critical for analyzing the effectiveness of different marketing channels and adjusting strategies accordingly.

Other options include dimensions that, while related to traffic sources, do not represent the default dimensions reported specifically for website visitors. For instance, campaigns relate to specific marketing efforts, but they are not part of the fundamental traffic source data like Source and Medium.