Metrics are how you measure your data and are used to assess the performance of your marketing or business activity. 

For example, you may track the number of 'Clicks' your ad campaign has garnered over time to determine how effective your ads are in bringing people to your site.

Base metrics: A base metric is a reflection of the data that is stored in our database which are unaltered. Typical base metrics would be such as Impressions, Clicks or Spend.

Composite metrics: Composite metrics are a combination of the base metrics which are usually used to create calculation on the base metrics. Typical composite metrics would be CPC, CTR or VTR

Calculated Metrics: The Bright Analytics data model allows you to apply logic and calculations on top of your existing data. These metrics aren't stored in the database but are used to query the data to do the calculation, for example if a multiplier is required.