How flash reads an xml from php file?

i just did the tutorial [size=4][color=#003366]Output mySQL data as XML with PHP.[/color][/size]
[color=#003366]i just didn’t understand one thing… i had one site done in flash with dynamic fileds that connect to a xml file… now with this php script i just have to replace the link to the old xml file on my flash site for this php file and i’m done? i understand that the php is outputed as xml but flash will understand that?[/color]
[color=#003366]please some one explain it to me…
thanks in advance.[/color]