# Peios

> The operating system itself — identity, tokens, security descriptors, processes, and the kernel subsystems behind them.

All of Peios as one markdown file: [/peios/print.md](/peios/print.md)

- [Peios Security Fundamentals](/peios/security-fundamentals.md): The Peios Security Model.
- [Using Peios](/peios/using-peios.md): Operating a Peios system — the registry, filesystems, and the everyday tools.
- [Advanced Peios](/peios/advanced-peios.md): The deeper end of Peios — internals and behaviour beyond everyday operation.
- [Developing for Peios](/peios/developing-for-peios.md): How to build software for Peios.
- [Peiso](/peios/peiso.md): The Peios image builder — from a declarative peiso.toml to a composed root, packed initramfs, UKI, and bootable live ISO.