1 2 3 "A declaration specifies the interpretation and attributes of a set of identifiers. A definition of an identifier is a declaration for that identifier that:
for an object [variable or constant], causes storage to be reserved for that object;
for a function, includes the function body;
for an enumeration constant, is the (only) declaration of the identifier;
for a typedef name, is the first (or only) declaration of the identifier."
