Ada Reference Manual (Ada 2022)
8 Visibility Rules
The rules defining the scope of declarations and the rules defining which identifiers, character_literals, and operator_symbols are visible at (or from) various places in the text of the program are described in this clause. The formulation of these rules uses the notion of a declarative region.
As explained in Clause 3, a declaration declares a view of an entity and associates a defining name with that view. The view comprises an identification of the viewed entity, and possibly additional properties. A usage name denotes a declaration. It also denotes the view declared by that declaration, and denotes the entity of that view. Thus, two different usage names can denote two different views of the same entity; in this case they denote the same entity.