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users-manual/01-what-this-is.md

@@ -11,6 +11,8 @@
 - [How you get the image](#how-you-get-the-image)
 - [What you can do inside](#what-you-can-do-inside)
 - [Experimental software](#experimental-software)
+- [Terminology you will see elsewhere](#terminology-you-will-see-elsewhere)
+- [What Bare OS is not](#what-bare-os-is-not)
 
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@@ -56,4 +58,18 @@ Bare OS is **not** a production operating system. APIs, disk formats, and networ
 
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+## Terminology you will see elsewhere
+
+- **Holepunch / Pear / Bare** — Bare OS targets the **Bare** JavaScript runtime and often ships as a **Pear** application. Your **host** may run Node for development even when the **image** expects Bare APIs.
+- **System drive vs personal drive** — Already introduced above; the handbook calls out routing rules, **`/.bare/`**, and mount namespaces in [Chapter 5](../handbook/05-identity-vault-and-hdms.md) and [Chapter 3](../handbook/03-protocol-and-disk.md).
+- **Stock image** — The tree produced from this repository’s **`kernel/`** plus built **`/bin`** and **`man.json`**, without your custom forks. Capability bits and **`ctx` API** versions describe what the **stock** booter and seeder advertise together; see [compatibility matrix](../docs/reference/compatibility-matrix.md).
+
+---
+
+## What Bare OS is not
+
+It is **not** a Linux distribution, a container runtime, or a full hardware OS. There is no kernel mode, no hardware driver model, and no guarantee that arbitrary **npm** packages run unchanged inside the guest. Treat the POSIX-like surface as **familiar ergonomics** backed by JavaScript and Hyperdrive semantics, not as a certification target.
+
+---
+
 _Previous: [User manual home](README.md)_ · _Next: [Chapter 2 — Install and repository layout](02-install-and-repository-layout.md)_