Update documentation for system.process.memory fields to include clar…

…ification on Windows memory terminology (#17268)

* update field description

* update changelog

* fix naming

* update

CHANGELOG.next.asciidoc

@@ -162,6 +162,7 @@ https://github.com/elastic/beats/compare/v7.0.0-alpha2...master[Check the HEAD d
 - Add capability of enrich `container.id` with process id in `add_process_metadata` processor {pull}15947[15947]
 - Update RPM packages contained in Beat Docker images. {issue}17035[17035]
 - Update supported versions of `redis` output. {pull}17198[17198]
+- Update documentation for system.process.memory fields to include clarification on Windows os's. {pull}17268[17268]
 
 *Auditbeat*
 

metricbeat/docs/fields.asciidoc

@@ -36077,7 +36077,7 @@ Memory-specific statistics per process.
 *`system.process.memory.size`*::
 +
 --
-The total virtual memory the process has.
+The total virtual memory the process has. On Windows this represents the Commit Charge (the total amount of memory that the memory manager has committed for a running process) value in bytes for this process.
 
 
 type: long
@@ -36089,7 +36089,7 @@ format: bytes
 *`system.process.memory.rss.bytes`*::
 +
 --
-The Resident Set Size. The amount of memory the process occupied in main memory (RAM).
+The Resident Set Size. The amount of memory the process occupied in main memory (RAM). On Windows this represents the current working set size, in bytes.
 
 
 type: long