The total number of conversion actions completed.

Overview:

Conversions is the total number of conversion actions that have occurred for options selected in the Global Filter. Conversion action types may include website conversions, call conversions, etc. and what actions are measured in each conversion category depends upon the setup in your Google Ads environment. 

While it is common to confuse Conversions to be synonymous with Leads, these are different metrics since your Ads specialist may configure other conversion actions to optimize ads performance & measurement. Use this metric if you are sure that you are indeed looking for Google Ads conversions. Use the Leads metric if you are interested in looking at the number of leads that were generated based upon your ads.  

Data Sources:

Adapter name, Adapter Name, ...

Formula:

N/A

or, How it's calculated for Calculated Metrics.