addressed at the very top of the article

   A note on terminology: Throughout this post I refer to "the BEAM." BEAM is
   the virtual machine that runs both Erlang and Elixir code, similar to how the
   JVM runs both Java and Kotlin. Erlang (1986) created the VM and the
   concurrency model. Elixir (2012) is a modern language built on top of it with
   better ergonomics. When I say "BEAM," I mean the runtime and its properties.
   When I say "Elixir," I mean the language we write.