The User Groups component is used to maintain user groups (from a security standpoint).
Users working in the same application are assigned to the same user group.It does not matter who actually defined a query in a user group. Every user assigned to the user group is able to execute the query.
Users in a user group need to have the necessary authorizations before they are able to change or redefine a query. Every user in a system can be assigned to several user groups.