Classifications are created by grouping (classifying) granular data from a source report. For example, you might want to analyze display ads, but they are mixed with email, partner, text ad, and social media campaigns. You can create groups so that you can analyze them separately.

Important: On May 10, 2018, we will begin limiting the functionality of date-enabled and numeric classifications. These classification types will be removed from the Admin and Classification Importer interfaces. From that date on, no new date-enabled and numeric classifications can be added. Existing classifications can still be managed (uploaded to, deleted) through the standard classification workflow, and will continue to be available in reporting.

Video overview of Analytics Classifications.