Argument: An argument is an expression which is passed to a function by its caller (or macro by its invoker) in
order for the function(or macro) to perform its task. It is an expression in the comma-separated list bound by the
parentheses in a function call expression.
The arguments that are passed in a function call are called actual arguments. These arguments are defined in
the calling function.
The formal arguments are the parameters/arguments in a function declaration. The scope of formal arguments is
local to the function definition in which they are used. Formal arguments belong to the called function. Formal
arguments are a copy of the actual arguments. A change in formal arguments would not be reflected in the