Each window and component can define its own security settings. These settings determine who can see and/or use the component. To define security for a component, right click on it and choose "Component Security". Here you can choose to implement a security policy different than that of your parent. In the Security Settings panel, restrictions chosen apply to unchecked roles.
In the Client, if the user does not match the role filter that you define, the component will be disabled or hidden and disabled. If a user with higher privileges logs in, the component will be useable again.
If you choose to disable a component, make sure that it is a component that actually does something different when it is disabled. For example, buttons and input boxes can't be used when they are disabled, but disabling a label has no effect.