guides/command-objects-and-forms/v3/guide/whatAreCommandObjects.adoc - grails-static-website - Git at Google

 As described in the https://grails.apache.org/docs/latest/guide/theWebLayer.html#commandObjects[Grails documentation],
 ____
 A command object is a class that is used in conjunction with data binding, usually to
 allow validation of data that may not fit into an existing domain class. *A class is only
 considered to be a command object when it is used as a parameter of an action.*
 ____

 While a domain class *can* be used as a command object, so also can non-domain classes defined
 in other files (or even classes defined in the same file as the controller using the class).
	As described in the https://grails.apache.org/docs/latest/guide/theWebLayer.html#commandObjects[Grails documentation],
	____
	A command object is a class that is used in conjunction with data binding, usually to
	allow validation of data that may not fit into an existing domain class. *A class is only
	considered to be a command object when it is used as a parameter of an action.*
	____

	While a domain class can be used as a command object, so also can non-domain classes defined
	in other files (or even classes defined in the same file as the controller using the class).