Fix the line about parallelism

Author: rakhi-prathap

modules/learn/pages/services-and-indexes/services/query-service.adoc

@@ -43,9 +43,9 @@ The Execution Engine then begins executing the plan.
 It performs Scan operations on the relevant index, using either the Index Service or the Search Service. 
 Next, it performs Fetch operations to get the actual data from the Data Service, and then uses this data for Join operations. 
 
-The Query Service processes the data further by applying Filter, Aggregate, Project, and Sort operations. 
-These operations often run in parallel, as represented by the vertically aligned groups of right-pointing arrows.
-Finally, it executes Offset and Limit operations to set the result size and starting point, and then streams the results back to the client.
+The Query Service processes the data further by applying Filter, Aggregate, Project, and Sort operations.
+These operations can run in parallel; in the diagram, small boxes within an operation block represent this parallel execution.
+Finally, the service executes Offset and Limit operations to set the result size and starting point, and then streams the results back to the client.
 
 For more information about each of these operations, see xref:n1ql:n1ql-language-reference/selectintro.adoc#query-execution-phases[Query Phases].