diff --git a/doc/manual/introduction/about-nix.xml b/doc/manual/introduction/about-nix.xml
index 54c18a1e6..56ec39916 100644
--- a/doc/manual/introduction/about-nix.xml
+++ b/doc/manual/introduction/about-nix.xml
@@ -161,13 +161,19 @@ library and the compiler) would have to built, at least if they are
not already in the Nix store. This is a source deployment
model. For most users, building from source is not very
pleasant as it takes far too long. However, Nix can automatically
-skip building from source and download a pre-built binary instead if
-it knows about it. Nix channels provide Nix
-expressions along with pre-built binaries.
+skip building from source and instead use a binary
+cache, a web server that provides pre-built binaries. For
+instance, when asked to build
+/nix/store/b6gvzjyb2pg0…-firefox-33.1 from source,
+Nix would first check if the file
+http://cache.nixos.org/b6gvzjyb2pg0….narinfo exists, and if
+so, fetch the pre-built binary referenced from there; otherwise, it
+would fall back to building from source.
+
Nix Packages collection