Xml parsers can be categorized, either by nature or by property setting, as validating parser and non-validating parser.
my program XML parser works fine and able to parse those xml element defined in those schema files even without access to internet,
my question is, how can XML parser find those schema files from internet even without access to internet ?
The easiest way to determine the kind of it yourself is to give the xml an element or something not "defined" in any of those schemas. If you can still parser it, the parser you are using is non-validating, otherwise it is validating.