Google Earth lets you see the information placed on top of the map of any particular area like the census or marketing information and images. The kind of file used to see this information on the program is called as KML.

File extension KML or Keyhole Markup Language format is utilized for storing geographic data that includes navigation maps and other driving instructions. This format was primarily developed for the desktop mapping software Google Earth. KML was developed as a way of saving geographic information which is readable by different mapping programs in a standard way.

Another online mapping application – Google Maps – also gives support to importing XML files onto the Internet; so the users can see and edit the navigation data. As the KML extension is a format developed by Google, it only takes few mouse clicks to add the data to Google Maps.

File extension XML stands for eXtensible Markup Language. It is a type of semantic programming language which is used to get and present data to users. XML files use this extension and they can be easily read by most web browsers and some computer programs. These documents are used on many Internet sites and the huge browser support for XML files lets the data to be displayed with users not noticing any difference. Such files are used in many applications which involve changing or dynamic data. XML is normally used to transfer data in between two websites. There are also other ways of identifying them apart from the extension.

The KML and XML extensions serve totally different purposes. KML is associated with Google Earth while XML is primarily used for transferring data between two websites.