File Extension

Often we do not know the meaning and function from the file extension. Though the file extension is useful to show the program-makers from the file. If there is no such thing as a file extension then we will be struggling to determine the program / software which is suitable to run the file. For example we have a file of MS. Office Word 2010 that extension. Docx and then we open it not with the program source file is created, for example, we opened it with MS. Office Word 2003 then the file will not open. Here is another example of a file extension