i need to distinguish the activities on a service depending on the widget (id,DisplayName,...) that call it.
I am not sure what you mean by that. Do you want to know when you call a service from a widget like "clicked" on a button?
Or do you want to track when services are called from widgets?
sorry for my delay.
The question is not when but who.
I'm using for a different button the same service. Is it possible, inside the service, know who called it (display name or label of the button)?
You can use contextID for a button widget. When you set the "ContextId" for buttons and pass it to services as a parameter, the service can know who called it.