Org is theoretically just a markdown format. In practice it starts out as a markdown editor with a bunch of neat features, and can become this omnibus of organization. There's a whole organizational ecosystem which uses org as a sort of lingua franca, so the more you sacrifice at its alter the more it all comes together. I use it to unify my todo list and calendar, and have it display what needs to happen both on an hour to hour level and day to day. I use it to pin emails I want to reply to with one key combo, and connect notes to each other any way I want. I have no idea if it's useful enough to justify the time I put into it. For most people, probably not. But I've gotten it to the point that it's just totally frictionless for me, and not a single other system I've ever used has been easy enough to stick to.

You’d have to try it for yourself and see.

It is much more capable than the things you mentioned. It can do technical documents up to thesis writing, with citations, references both document internal and external, have code blocks, which can be run, using multiple langs per file, use output of one as input for the other, spreadsheets with a whole programming lang or GNU calc behind them, per formula of course, not only per spreadsheet, it can schedule events, it can use library of babel, it can do literate programming, ...

Need I say anything more?

You start with an outline.

You bolt literate programming onto it.

Then you tell your code blocks they can send input and output to each other via text in the document. Now you've got an excruciatingly well documented multi-language pipeline.

Then you get the source data for all your analyses in real time from [wherever they came from].

Then you render it _beautifully_ with your dependency graph documentation generated from graphviz (which graph data was newly inferred on this very run).

My first org-mode killer app, years and years ago was a monthly billing collection and analysis for a backup system I was running. The first pass took me a week to figure out how to collect and analyze. A few iterations later it was literally open the org-mode document and tell it "Do the thing". All my intermediate work was shown, everything was clear and open to inspection, and beautifully typeset. And I could generate it as HTML if they wanted it in a web page. (at the time they wanted PDF).

This is one of the ways org-mode is great. There are others. :)

> I really can't say I have understood, what exactly org-mode is supposed to be.

It's primarily two things:

1. A markup syntax

2. a TODO manager. It's flexible enough that you can come up with your own custom TODO workflows (e.g. GTD, etc). You can do queries on a fair amount of metadata to construct your TODO list.

In support of all that, it has good table features (you can do spreadsheet like functionality in them), code management (execute source code blocks similar to Jupyter, but you can have code in multiple languages communicate with one other), link to just about anything (with a bit of setup, I can even link to Outlook emails). While in the middle of your work, you can capture notes and/or TODOs and have them filed away in the appropriate file and location within that file.[1] Finally, you can export into many formats (I don't write pure LaTeX any more - I always export an org file to LaTeX).

Example of a simple thing I do.

I read an email. It contains actionable information. With a keystroke, I create a TODO item in org mode, which contains a link to the email. Later when browsing my TODOs, I have access to the context.

Likewise, I'm reading an article in Chrome/Firefox, and I want to file it away for some reason. With a click on a bookmarklet, it sends the URL and related info to Org mode in Emacs and it is filed away.

A more sophisticated example that required some elisp: I take meeting minutes at work. Any time something comes up where a TODO is assigned to a person, I hit a keystroke and type in the TODO. It finds the heading called "Action Items" for that particular meeting and files it there. At the end of the meeting, I export the minutes into HTML or Word and email it out.