>>6205In simple terms, org-roam expands upon org's capabilities by adding a system for linking between notes and maintaining a database for storing the link relationships between files.
A big advantage is that it gets rid of the hierarchical nature of your file system. You never have to worry about which directory a certain file or note goes in because the system is tag/link based. Org Roam works via a flat directory structure. You just dump org files in this directory and roam will automatically add it to its database, allowing you to fuzzy search for files nicely, using Ido/Ivy/Helm/whatever you use.
This lack of a clear hierarchical structure is only made more useful by the linking system: following the zettelkasten method, you're supposed to take short notes instead of monolithic ones and link them together instead of dumping all info into one big file. This allows you to navigate your knowledge base via links and backlinks a lot more easily, since each piece of information is self contained but also connected to all its related pieces of info. The real kicker of this zettelkasten system is that it also allows you to derive more knowledge from each note, strange as it may sound; since each note is a small, self-contained but interlinked bit of info, by navigating around the zettelkasten, you end up finding connections you wouldn't have otherwise. You start connecting the dots between different ideas and coming up with new things. It's quite a nice system.
As for real world usage, I use it for everything. For the obvious, more academic purposes, which involve my university studies, but also any personal ones (reading Capital rn and this is pretty handy to have), but also non-obvious usage. If I see an important news article, I put it into the zettelkasten. See an interesting blog post? Yep, into the database it goes. Have to run some obscure esoteric shell command and would like to recall it easily in the future? Again, put it in the zettelkasten. Org roam shines at allowing you to quickly dump information into text files, and later recalling it with ease. The information you need is at your fingertips, and the info you don't need is neatly tucked away for when you do.
Gif related is a quick demo of me aimlessly browsing around my roam db. Notice how I can quickly search through file titles using my preferred minibuffer completion framework (Ivy), and then later search through the contents of all files using Deft. To get the fancy graph from my post above, I use an external package called org-roam-server.