In Elixir, what's the difference between a node and a process?

Question

This question is tagged "Erlang" as well, because these Elixir modules more or less just wrap Erlang functionality.

Nodes seem like named processes. They can execute functions concurrently, link to other nodes, and act like process supervisors. Many of the functions in each module appear to be the same, strengthening the similarities.

What is value of the Node module? What does it offer that Process doesn't?

Answer 1

Nodes seem like named processes.

It seems you've misunderstood what a Node is. A Node is an instance of the Erlang VM, running as one Operating System process. An Erlang Process is a unit executing code, similar to an Operating System thread but lighter. An Erlang Process runs on an Erlang Node, just like Operating System processes run on an Operating System. An Erlang Process cannot run without an Erlang Node.

Answer 2

It's two distinct concepts. A node is an instance of an Erlang virtual machine and a process is a very lightweight thread running inside the virtual machine.

Here is the definition of an Elixir process, according to the documentation :

In Elixir, all code runs inside processes. Processes are isolated from each other, run concurrent to one another and communicate via message passing. Processes are not only the basis for concurrency in Elixir, but they also provide the means for building distributed and fault-tolerant programs.

Elixir’s processes should not be confused with operating system processes. Processes in Elixir are extremely lightweight in terms of memory and CPU (unlike threads in many other programming languages).

And a node is the representation of an Erlang virtual machine. Here is some examples of functions of the node module :

alive?()

Returns true if the local node is alive

connect(node)

Establishes a connection to node

disconnect(node)

Forces the disconnection of a node