Update 2-understand-subqueries.md

fixing unit

Author: MScalopez

learn-pr/wwl-data-ai/write-subqueries/includes/2-understand-subqueries.md

@@ -11,5 +11,5 @@ The purpose of a subquery is to return results to the outer query. The form of t
 
 In addition to the choice between scalar and multi-valued subqueries, subqueries can either be self-contained subqueries or they can be correlated with the outer query:
 
- *  Self-contained subqueries can be written as stand-alone queries, with no dependencies on the outer query. A self-contained subquery is processed once, when the outer query runs and passes its results to that outer query.
+ *  Self-contained subqueries can be written as stand-alone queries, with no dependencies on the outer query. A self-contained subquery is processed once, when the inner query runs and passes its results to that outer query.
  *  Correlated subqueries reference one or more columns from the outer query and therefore depend on it. Correlated subqueries cannot be run separately from the outer query.