الأخوة الكرام أحب توضيح لمعني كلمة مناداة الدالة وجزاكم الله عنا كل خير

You can call Function by put the output of the function on a variable which is the same type,
as the output of the function

example
let's say that we have function called get_name,which return the name of the employee as this

create or replace function get_name(p_empno number) return char is
v_name varchar2 emp.ename%type;
begin
select ename
into v_name
from emp
where empno = p_empno;
return v_name;
exception
when no_data_found then
return ('*****');
end;
-----
------
and now we are going to call this function first by select statment;

select get_name(empno) name
from emp;
---
---
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and the other way is

declare
v_name varchar2(60);
begin
v_name := get_name(12);
end;