Click on the related link below to see the applications that use MD file extensions.
.mdb is the file extension used by Microsoft Office's Access program and it marks a file that is a database.
Access
That would be layer 7 - the application layer.
An application is a program (generally an executable file .exe) that can be run on your system. Windows Media Player would be an application, as would Internet Explorer.
A file with a .cfg extension is usually a configuration file. The file will be used by an application to load all the configuration settings. There is no standard format for a .cfg file and how it can be modified will differ from application to application.
.txt, or a text file can always be opened by an application.
.txt, or a text file can always be opened by an application.
You can find out the file type by searching on http://filext.com/ and then you can see what programs you can use to open that file. Hope this helps.
True
Adobe Acrobat
an application runs a series of commands. a file is data stored in some retrievable way.
You can file Form I-539 for your application with the United States Citizenship and Immigration Services (USCIS).