I searched for package management on Erlang and Elixir and got some pointers to rebar rebar3 mix hex and relx etc. Can you help clarify the relationships among them? Where to use what? Is package just synonym to Erlang's application made up of modules?
A package is synonym to Erlang or Elixir application/ library made up of one or more modules
Hex is currently the preferred package manager for the Erlang ecosystem (ERLANG, LFE, JOXA & ELIXIR)
rebar3 + hex.pm: For Erlang package management rebar3 uses hex.pm, a package manager for Erlang and Elixir packages. more Documentation
mix + hex.pm: For Elixir package management mix uses hex.pm, a package manager for Erlang and Elixir packages. more Documentation