It is all correct.... it is the essence of using a function
/* Being of the FUNCTION-BODY
PARAMETER $name is used as a =local= VARIABLE
the =local= $name VARIABLE will get its VALUE
as you =call= the greetings() function
using 1 ARGUMENT in this case the =string= Value "Cole"
echo "Greetings, " . $name . "!";
you have defined a greetings() function which takes 1 parameter $name
As you call / execute the greetings function
and the greetings() function was defined as having 1 parameter
you will have to provide 1 argument in this case the string Value "Cole"
some quotes from the outer-world:
argument is the value/variable/reference being passed in,
parameter is the receiving variable used within the function/block
parameters" are called "formal parameters",
arguments" are called "actual parameters".