Since 2007, Microsoft began to use a file format docx, which is created by using the Office Open XML. The format is a zip-file containing the text in the form of XML, graphics and other data that can be translated into a sequence of bits using patent-protected binary formats. At first it was assumed that this format will replace the doc, but both formats are still used today.
DOTM file has two attributes namely Zip file compression and XML (Extensive Markup Language). It is identical to .DOCX and .DOCM file in which the M stands for macro and the X stands for XML. The application that can open both .DOCX and .DOCM is via Microsoft Word version 2007 or 2010.