They are different things - The Command Prompt is Not MS-DOS - but as far as the user is concerned they could be the same thing as they do the same things.

So it depends on your point of view. From a technical point of view your friend it correct, but from a user perspective you are correct (sort of as there are differences that an expert would spot).

No.

^{(Unless your definition of equality does not extend past »It is a text interface and I can run programs from it.«)}

What is run when you click Command Prompt in the Start Menu is the Windows Command Processor, a.k.a. cmd.exe. Its built-in commands and scripting syntax (including many quirks) are based on the ancient command.com from CP/M and later MS-DOS, but apart from that they are completely separate things. Also, command.com is a 16-bit program while cmd.exe is a native Windows console application.

Things were different in Windows 95, 98 and ME where command.com would be run in a MS-DOS VM with Windows acting as the hypervisor (yes, they had that sort of thing at the time already). There you had an entire virtual machine running DOS. But on Windows NT, 2000, XP, Vista and 7 – no. DOS only lives on there in ntvdm.exe which is the NT Virtual DOS Machine which is just a thin emulation layer capturing calls that the CPU cannot execute directly (which is why it works faster but worse than DOSBox).

In any case, even command.com was just a shell for DOS. It wasn't the operating system.

Inside, I actually cringe each time I see people referring to a window with gray-on-black text as MS-DOS. In the vast majority of cases they don't actually know what they're referring to.

From what I understand, MS-DOS is the disk operating system that Microsoft released. The command prompt is a non-graphical interface that allows you to interact with your operating system.

Command Prompt is a command line interpreter application available in most Windows operating systems, officially called the Windows Command Processor but sometimes called the command shell. Command Prompt is a Windows program that emulates many of the command line abilities available in MS-DOS but it is not actually MS-DOS.

Command Prompt is a GUI version of command.com in MS-DOS. cmd.exe is a native Windows application usually running in a Win32 console. This allows it to take advantage of features available to native programs on the platform that are otherwise unavailable to DOS programs.

For example, since cmd.exe is a native text-mode application on OS/2, it can use real pipes in command pipelines, allowing both sides of the pipeline to run concurrently. As a result, it is possible to redirect the standard error in cmd.exe, unlike COMMAND.COM. (COMMAND.COM uses temporary files, and runs the two sides serially, one after the other.)

In reality, cmd.exe is a Windows program that acts as a DOS-like command line interpreter. It is generally compatible, but provides extensions which address some of the limitations of COMMAND.COM (above explanations are referred by Wikipedia).

Your friend is right. MS-DOS is/was an Operating System (Microsoft Disk Operating System is what the acronym stands for.) The UI for DOS is called a (the) command prompt.

The first few versions of Windows ran on top of DOS (making them technically operating environments, though I'm not sure anybody makes that distinction anymore), but later OSes, starting with the NT Kernel, didn't - DOS was gone.

However, people still needed the functionality provided by the command prompt, and instead of command.com we got command.exe (and these days cmd.exe), which when run gives us a command prompt.

But, that's not the only (nor anywhere near the first) command prompt that people have used. Command Prompts are also called Shells, and Unix has many, and the commands are different and often very powerful. Speaking of Power, Microsoft has created a new command prompt for Windows called PowerShell which is incredibly powerful and interesting. See Wikipedia for more: http://en.wikipedia.org/wiki/Command-line_interface#Operating_System_Command-Line_Interfaces

They're not the same

Apparently lots of people don't realise that the DOS Prompt, and the Windows Command Prompt are not the same thing. They're actually two different programs - COMMAND.COM and CMD.EXE respectively.

Know Your Command Prompts

Firstly due to differences in the platform (DOS vs Windows) and interpreter (command.com vs cmd.exe), there will be obvious dissimilarities like

• DOS runs in fullscreen without a windowed mode, so no mode con:cols=COL lines=ROW command to resize the console, and no title command


• DOS doesn't support multitasking, multiuser, registry, permissions, long file names, symlinks/hardlinks, network, Unicode, dynamic disks and advanced volumes support... so no tools to manage those

But there are also major differences in the capabilities and syntax of internal commands between command.com and cmd.exe, as well as some external tools in the two environments. In MS-DOS there are

• 
  

  No functions, code blocks () and local scopes which mean

  
  
  
  
  
  • 
    for, if... must be followed by a single command on the same line
  
  
  • no exit /b or goto :eof
    
  
  
  • no setlocal and endlocal
    
  
  
  • 
    goto can only jump to a label, call can only start another batch file
  
  
  • 
    

    commands can't be grouped together like

    
    
    

    (
    
    command1
    
    command2
    
    ) >output.txt
    
    

    
    
  
  
  
  



• No escape character ^. Printing special characters would be a pain, and no possibility of running multiline commands



• No special formats of if
  
  
  
  
  • no if cmdextversion and if defined
    
  
  
  • no numeric and case-insensitive string comparison if [/i] string1 compare-op string2
  
  
  
  


• No command history and command argument completion


• No indirect expansion (e.g. call set %%var%suffix%=string) of variables and no delayed expansion (e.g. echo !var%suffix%!)


• No advanced string manipulation
  
  
  
  
  • no ~xxxV variable support
    
  
  
  • no substring %variable:~num1,num2% or string replacement support %variable:str=newstr%
    
  
  
  
  


• No partial variable name matching for set, and
  
  
  
  
  • no set /a so you can't do arithmetic
  
  
  • no set /p which means reading user input is a pain
  
  
  • no set "var=value" syntax
  
  
  
  


• No for /d, for /r or for /l. No for /f so reading input from files is also difficult. The only form of for in DOS is FOR %variable IN (set) DO command [command-parameters]
  


• No findstr, and find doesn't support Unicode


• No special environment variables like %CD% %DATE% %TIME% %RANDOM% %ERRORLEVEL% %CMDEXTVERSION% %CMDCMDLINE% %HIGHESTNUMANODENUMBER%
  


• Limited directory changing ability
  
  
  
  
  • No pushd/popd
    
  
  
  • No cd /d. Also no cd path with spaces and cd "path with spaces" due to the lack of long file name support
  
  
  
  


• No color
  


• No forfiles
  


• No assoc (because there are no GUI and files must be opened manually from command line, so no file association is needed)

A lot of useful external commands in Windows like where, sort, more (in some DOS versions), choice... are also missing in DOS

And this is what MS' Rich Turner said

Also, Cmd != MS-DOS!

I also want to point out a common misconception perpetuated by articles like the ones above: Cmd <> MS-DOS!

In FACT:

• Microsoft last shipped a "new" version of MS-DOS (v8.0 in Windows ME), on September 16th, 2000 - 16 years ago (as of this writing)!!


• MS-DOS was an operating system (albeit a relatively simple OS by today's standards) whose primary user-interface was a command-line shell, until Windows 3.x & 9.x arrived and ran on/around MS-DOS


• MS-DOS' command-line shell's scripting language was relatively terse and moderately powerful, but lacked many of the richer, and more advanced features we enjoy in modern-day PowerShell, Bash, etc.


• While later versions of MS-DOS grew in sophistication and added/replaced some older assembly with new code written in 'C', much of MS-DOS remained written in x86 assembly for efficiency, and because it was the only way at the time to gain access to many hardware devices and peripherals. This made MS-DOS non-portable to non-x86 CPU's. If you're so inclined, you can actually download the source code for MS-DOS v1.1 and v2.0 to see just how much of the earlier versions of MS-DOS were written in x86 assembly (hint: pretty much all of it)!

https://blogs.msdn.microsoft.com/commandline/2017/01/04/rumors-of-cmds-death-have-been-greatly-exaggerated/

Further reading

• Limitations of MS-DOS 6.22


• Commands and Their Availability From MS-DOS 6.22 through Windows 8


• New (and Removed) Commands in Windows 8


• How do modern .bat files differ from old MS DOS .bat files?


• Windows batch files: .bat vs .cmd?


• cmd.exe: comparison with MS-DOS Prompt

In conclusion, functionality-wise they may be a little bit similar, but otherwise hugely different