Both .docx and .docm are digital file extensions available from the Microsoft Office 2007suite. A file extension indicates to the computer what type of file it is, how it is encoded and what program(s) may open it. .docx and .docm are two of four file extension from Microsoft Office 2007.
The .docx extension is the default for Microsoft Word 2007 and 2010 files. When opened with Microsoft Word, these files represent stored properties and sub folders. As the default file extension for Microsoft Word, the .docx extension does not contain macros. Macros are shortcuts to tasks and in Microsoft Word 2007 and 2010 are generally automated tasks dealing with formatting. Although .docx files are viewable through a number of plain text programs, they are specifically designed to be opened and used via Microsoft Office 2007 and 2010. The file is associated with XML (Extensible Markup Language), the programing language of the most recent Microsoft Office Suites.
The .docm file is another extension for and from Microsoft Office 2007 and 2010. This type of file extension represents that the file contains macros or has macros enabled. These files have specific information and formatting properties related to spreadsheets, charts, presentations, memos, and word processing information. Since they save this type of information for quick and automated use, they tend to save users time and effort. They will need to be opened by Microsoft Office to utilized the available macros.
Main Differences Between .docx and .docx
Although both .docx and .docm files are associated with Microsoft Office 2007 and 2010, most users will find that they generally use .docx as default. Both files represent the available macros, and the easiest way to differentiate between to two is to note that the 'm' in .docm represents 'macros', while the 'x' in .docx simply represents the 'XML' language and does not contain macros. Simply put, .docm files have macros enabled, .docx files do not.
Errors associated with .docx and .docm extensions
Most users will learn of these file extensions by the errors associated with them. Since they can contain macros, they will need to be opened using Microsoft Office. If they are opened by other programs, or if Microsoft Office is not availalble on the computer, an error message will explain that these files may not be properly viewed, or may only be viewed in plain text. .docm files can also contain malicious properties if received from an unreliable source, so it is better not to open this type of file without using a virus scanner.