KML is a format that displays geographic data in an Earth browser. Google Earth and Google Maps use these files to pinpoint locations. This file was created for Google Earth that was going to be named Keyhole Earth Viewer. It has since expanded passed other projects besides Google Earth such as Marble. KML has some of the same structure as GML. KML was tailored to Google Earth and is a language for the visualization of geographic information while GML is a language meant to encode geographic content.
GML stands for Geographic Markup Language. GML is used as a modeling language for other geographic systems on the internet.
In addition to the problem described above, i.e. the lack of the appropriate application to support the .KML file, there may be several reasons that cause problems with opening and operation of the data format:
A quite common problem is the lack of application in the appropriate version. Even if you have an application, with the help of which you should open the .KML file, you may have a problem with it because of its version. Perhaps in previous versions the application has not yet supported the .KML file, so download the update and check again.
If you have already installed the appropriate application, and it is the correct version, the file may not open correctly, because the operating system does not have information that this program supports the file. So you need to "show" which program the computer should use. To do this:
It also happens that the file you want to open is corrupt and therefore there is no such possibility. In this situation, you should find its different version, or ask a person from whom you got, to send it again.
There may be several reasons why you cannot open the file with .KML extension. Directly on this website you can find a solution of the most common problem with the .KML file – that you do not have on your computer the appropriate program to open the file.