message: Add a "shell vs terminal" section to Niksa.md
  I've typed this up way too many times now. I'm sticking this comment in Niksa.md, and if it's ever an insufficient explanation of the differences, we can elaborate.
diff: @@ -9,6 +9,8 @@ This document serves as a storage point for those posts.
  - [Output Processing between "Far East" and "Western"](#fesb)
  - [Why do we not backport things?](#backport)
  - [Why can't we have mixed elevated and non-elevated tabs in the Terminal?](#elevation)
  +- [What's the difference between a shell and a terminal?](#shell-vs-terminal)
  +
  ## <a name="cmd"></a>Why do we avoid changing CMD.exe?
  `setlocal` doesn't behave the same way as an environment variable. It's a thing that would have to be put in at the top of the batch script that is `somefile.cmd` as one of its first commands to adjust the way that one specific batch file is processed by the `cmd.exe` engine. That's probably not suitable for your needs, but that's the way we have to go.
  @@ -179,3 +181,20 @@ Other platforms have accepted that risk in preference for user convenience. They
  Original Source: https://github.com/microsoft/terminal/issues/632#issuecomment-519375707
  +## <a name="shell-vs-terminal"></a>What's the difference between a shell and a terminal?
  +
  +_guest speaker @zadjii-msft_
  +
  +I think there might be a bit of a misunderstanding here - there are two different kinds of applications we're talking about here:
  +* shell applications, like `cmd.exe`, `powershell`, `zsh`, etc. These are text-only applications that emit streams of characters. They don't care at all about how they're eventually rendered to the user. These are also sometimes referred to as "commandline client" applications.
  +* terminal applications, like the Windows Terminal, gnome-terminal, xterm, iterm2, hyper. These are graphical applications that can be used to render the output of commandline clients.
  +
  +On Windows, if you just run `cmd.exe` directly, the OS will create an instance of `conhost.exe` as the _terminal_ for `cmd.exe`. The same thing happens for `powershell.exe`, the system will creates a new conhost window for any client that's not already connected to a terminal of some sort. This has lead to an enormous amount of confusion for people thinking that a conhost window is actually a "`cmd` window". `cmd` can't have a window, it's just a commandline application. Its window is always some other terminal.
  +
  +Any terminal can run any commandline client application. So you can use the Windows Terminal to run whatever shell you want. I use mine for both `cmd` and `powershell`, and also WSL:
  +
  +![image](https://user-images.githubusercontent.com/18356694/89556758-79d27e80-d7d7-11ea-84e2-10710e09ef4a.png)
  +
  +It's not the Terminal's responsibility to remember the commands executed by a commandline client. That's the responsibility of the _shell_. How would the terminal remember commands executed by something like `emacs` or `vim`? Those are both applications where the user is typing input and hitting enter, like they would at a cmd prompt, but without something that resembles a command history.
  +
  +Original Source: https://github.com/microsoft/terminal/issues/6500#issuecomment-670035468
  