can anyone tell me why my PHP script contains the characters ","

[leekheed]

may sound stupid but can anyone tell me why my PHP script contains the characters ","

example

$comma_separated = $fullname . "," . $zodiac . "\n";

[audiopro]

Comma separated files are very common and this looks like a very simple version of one.
If you were trying to keep a number of variables together - ie. Firstname, Lastname, Username and Password, saving Them to a variable as 'John,Doe,JOHN114,ABCD1234' would allow you to split the variable, on the commas, and get all the separate variables back as an array.