If you've been watching tutorials about Claude Code skills, you've probably noticed that almost everyone talks about building custom skills. Which is great! But it left me confused for a while, because it felt like I was missing something.
Turns out, there are actually 3 different types of skills — and understanding the difference made everything click for me. Let me break it down simply.
🔍 First, what even is a skill?
A skill is a reusable set of instructions stored in a SKILL.md file that Claude loads when it's relevant. Think of it like a recipe card you hand to a very smart chef — the chef already knows how to cook, but they don't know your family's secret sauce.
Skills are part of the Agent Skills system, which works across Claude Code, claude.ai, and other AI tools. Same format, different surfaces.
Now, the 3 types:
1. Pre-built skills (Anthropic bundled) 🟣
These ship with Claude Code and claude.ai — no setup, no config, they just work behind the scenes.
You've already been using them every time you ask Claude to create a file. The document creation skills — docx, pdf, pptx, xlsx — are all pre-built skills that Anthropic maintains. When you say "create a presentation about X", Claude quietly loads the pptx skill and follows those instructions.
Anthropic has even made the source of these skills available on GitHub if you're curious to see how a production skill is built. It's a great reference for when you want to create more complex skills yourself.
You don't need to do anything for these. They're just there. ✅
2. Community / ecosystem skills 🟢
These are skills built by the community and shared through the skills ecosystem. You can browse them at skills.sh and install them with one command:
npx skills add anthropics/skills --skill skill-creator
One cool thing about community skills: they follow an open standard, which means the same skill works across multiple AI tools — Claude Code, GitHub Copilot, Cursor, and more. Install once, use everywhere.
# See what you have installed
npx skills list
# Search for something specific
npx skills find
Great for: workflows other people have already figured out so you don't have to. ✅
3. Custom skills (your own) 🟠
This is what all those tutorials are about — and honestly, it's the most exciting one.
You create a folder, drop a SKILL.md file inside, and that's it. Claude discovers it at session start and uses it when it's relevant (or when you call it directly with a /slash-command).
You can store them in two places:
-
Project-level →
.claude/skills/your-skill-name/SKILL.md(only available in that project) -
Global →
~/.claude/skills/your-skill-name/SKILL.md(available from anywhere, always)
The structure is always the same: a YAML frontmatter block with a name and description, then your instructions below. The description is what Claude uses to decide when to load it automatically, so make it specific.
---
name: my-skill
description: What this skill does and when Claude should use it
---
# My Skill
Your instructions here...
Great for: teaching Claude your conventions, your tone, your team's way of doing things. ✅
The pattern that helped me
Here's how I now think about it:
| Type | Setup needed? | Who creates it? | Where it lives |
|---|---|---|---|
| Pre-built | None | Anthropic | Ships with Claude |
| Community | npx skills add |
The community | skills.sh |
| Custom | Create a folder + file | You | .claude/skills/ |
The reason most videos focus on custom skills is that the other two types just... work silently. There's nothing to teach because there's nothing to set up. The interesting content — the "here's what I built for my workflow" — is always custom.
Where to start?
If you're new to this, I'd suggest:
- Notice the pre-built ones — next time you ask Claude to make a document, know that a skill is running under the hood
- Browse skills.sh — there might already be a skill for something you do every day
-
Build your first custom skill — even a simple one. I recently built a
health-buddyskill that reminds me to take breaks when I'm deep in a coding session (and yes, it triggers when I type "I'm going insane" 😄). It took 10 minutes and one file. Check it here
📖 Want to go deeper? The official Claude Code skills docs are genuinely good and beginner-friendly.
The skills system clicked for me once I understood that custom is just one type — and that I was already benefiting from the others without even knowing it.
Have you built a skill yet? Drop it in the comments — I'd love to see what you've made! 👇
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