Update content/2020-12/core/id.markdown

Co-authored-by: Juan Cruz Viotti <[email protected]>

content/2020-12/core/id.markdown

@@ -20,7 +20,7 @@ Generally, `schema` and `schema resource` might create confusion. Let's clarify
 
 **Schema**: This refers to the entire JSON boolean or JSON object passed to an evaluator.
 
-**Schema Resource**: A schema may consist of one or more schema resources, and a schema resource is essentially an `$id` boundary. When you introduce nested schema objects with `$id` in your schema, you create new schema resources.
+**Schema Resource**: A schema may consist of one or more schema resources (`$id` boundaries). When you introduce nested schema objects with `$id` in your schema, you create new schema resources.
 
 **Schema Object**: This is a single subschema in the schema tree, considering only its immediate keywords and not including nested subschemas.