Channels

Channels are the main repositories of packages/derivations on Nix. A channel is just a URL that points to a place that has many Nix expressions and a manifest. The most popular (and actually probably the only channels anyone use) are nixpkgs channels (for instance nixpkgs unstable or nixpkgs 23.05.

We'll dig deeper in nixpkgs on itself because it's really huge, but for now the only thing you need to know is that it's a git repo where each branch is a channel.

So in a nutshell, you subscribe to a channel, then each time you'll try to download a package, you will be able to get it through that channel.

We'll also dive later in something called flakes that are seen as decentralized alternatives to channels.