# Glossary

```{glossary}
Nix
    Build system and package manager.

    Read /nɪks/ ("Niks").

Nix language
    Programming language to declare packages and configurations for Nix.

Nix expression
    Expression written in the Nix language.

Nix file
    File (`.nix`) containing a Nix expression.

Nixpkgs
    Software distribution built with Nix.

    Read /nɪks ˈpækɪʤɪz/ ("Nix packages").

NixOS
    Linux distribution based on Nix and Nixpkgs.

    Read /nɪks oʊ ɛs/ ("Niks Oh Es").

reproducible
    Reproducibility would guarantee exactly the same results no matter
    **when** or **on what machine** you run the command.
```