# Sandboxing

Whenever Nix builds anything, it _sandboxes_ that process from everything else on the host system.
Nix builds are sandboxed for a variety of reasons:

1. The ensure [reproducibility].
   Sandboxing ensures that no system state on the host machine affects the build outcomes.
1. To maintain strict [provenance].

[reproducibility]: /concepts/reproducibility
[provenance]: /concepts/provenance