Update episodes/02-sql-aggregation.md

Co-authored-by: James Foster <[email protected]>

episodes/02-sql-aggregation.md

@@ -226,7 +226,7 @@ Write a query that returns, from the `species` table, the number of
 
 ## Solution
 
-This query counts the number of species records that contain each value of the `taxa` field and names that result `species_count`.
+This query counts the number of times each value (Bird, Rabbit, Reptile or Rodent) in the `taxa` field occurs, defining a new field named `taxa_count` to hold the result.
 The `GROUP BY` clause means the query will create an aggregated table with one row for each taxa.
 Only those `taxa` values that have more than ten records will be included because of the `HAVING` clause.
 This filtering is applied _after_ grouping has been done.