Everything is stored in your device. You can back them up, encrypt and process however you want to. Works completely offline. Read your notes anytime, anywhere.

Variety of settings, and community themes & plugins, available from built-in marketplace. Every community plugin is open-source which means you can learn from it and develop your own.

This allows you to link notes back and forth really easily.

It's becoming more powerful everyday, it seems like they add many functions within several days.

Linking notes is a game changing feature. Very easy to use and link notes. Their implementation of markdown doesn't deviate from the standard form of markdown and so the same files can be used by other markdown programs without any consequence.
While renaming note link still works.

A Vault in Obsidian is like a database. Internal links and files are not shared across Vaults. Each Vault is opened with a separate instance of Obsidian. Each Vault can have its unique app settings and plug-ins. Useful if you have distinct/unrelated projects or "data spaces" requiring different workflows and data relations.

Ability to tag-as-you-write and find each occurrence of a tag in the entire vault makes it very easy to organize and retrieve notes. Supports nested tags.

In Obsidian, pane = window = note = page

Obsidian allows you to open as many notes as you can fit concurrently in your screen. You can split a pane horizontally/vertically. You can lock/link panes so they scroll in sync, useful for and edit & preview modes.

Also open for anyone to develop their own extensions/plugins.

Daily Notes plug-in, when clicked, generates a new note with the current date. Great for journaling and reduces friction in your writing habit.

You can create a custom template for your Daily Note.

The Graph view is more than an aesthetic gizmo. It allows you to grasp and recognise clusters of information, follow branches and easily filter out what you don't want to see. The "animate" option shows how your notes and links have grown organically. With a bit of tweaking to the visuals and the proper theme, your graph might even start to look like a disturbingly "alive", eerie thing.

A plugin that, when clicked, surfaces a random note from your vault.

This is a big difference, as having to read through long-form texts laden with [[links]] gives friction.

Easily turn your notes into simple yet sleek powerpoint-style presentations by enabling the Slides plugin and adding the --- separator.

Hotkeys can be customized in settings.
Can switch on or off Vim key bindings in the editor settings.

The onboarding consists of well-written help documentation (saved as a vault) served in small chunks and organized systematically so that you become familiar with all its features as well as get hands-on experience in real time.

Due to the tool being very developer-friendly, there are tons of cool developments being made to it by 3rd party devs.

When you hover on an internal [[link]], you get to preview the note without opening it on a new pane.

Page preview plugin must be enabled.

The app doesn't frustrate the user - the built-in help is excellent.

Variety of file formats are directly embedded in the markdown preview, e.g. markdown, image, audio, video and PDF files.

Allows exporting your markdown files as PDFs rendered with all of your plugins.

Daily and Weekly notes with Calendar Plugin.

A pretty, alternative way to represent links between your notes.

A feature unseen in other tools.
From the help doc, "This can be useful when modifying a lot of lines in the same way, for example putting - at the beginning of multiple lines to turn them into a list, or appending [[ to a series of links you’ve copied from elsewhere."

Supports extended searching by default. Community plugin called "Vantage" allows to make more advanced queries.

Version Control for your vault with Obsidian Git plugin.

Allows to refer to a note with multiple names.

There's a Discord server and a forum. Join the community!

No lock-in to a certain company - just markdown files on disk.

Available as a plugin.

Uses MathJax.

Allows to create templates with built-in plugin. There's also powerful community plugin called "Templater".

Uses Mermaid.

You can link to a block - e.g.: paragraph, blockquote, heading.

Add a custom metadata to a note with YAML front matter.

With Excalidraw.

Supports Citations and provides inserting from Zotero.

Advanced queries for the data-obsessed with Dataview Plugin.

Saving and loading workspaces.

With other options like notion, we can not see how the data is actually stored.

Use HTML in a note.

Variety of planning and organization plugins, such as Kanban boards or Day Planner.

Supports importing from tools such as Notion, Evernote, OneNote, Apple Notes, Bear, Zkn3, TiddlyWiki 5, and Roam Research. Refer to Obsidian Help for more info.

Translations are made by the community at GitHub repository.

Update your Discord status to show your friends what are you working on with Discord Rich Presence plugin.

When taking notes, you can just grab a print screen from your clipboard and paste into the notes without having to do any file management