Process.whereis

You're seeing just the function whereis, go back to Process module for more information.

whereis(name)

whereis(atom()) :: pid() | port() | nil

Returns the PID or port identifier registered under name or nil if the name is not registered.

See :erlang.whereis/1 for more information.

Process.register(self(), :test)
Process.whereis(:test)
#=> #PID<0.84.0>
Process.whereis(:wrong_name)
#=> nil