Purpose of Process.sleep(:infinity)

Hi all

Could someone please tell me, what is the purpose of Process.sleep(:infinity).

The code is from:

defmodule A do
  use GenStage

  def init(counter) do
    {:producer, counter}
  end

  def handle_demand(demand, counter) when demand > 0 do
    # If the counter is 3 and we ask for 2 items, we will
    # emit the items 3 and 4, and set the state to 5.
    events = Enum.to_list(counter..counter+demand-1)
    {:noreply, events, counter + demand}
  end
end


defmodule C do
  use GenStage

  def init(:ok) do
    {:consumer, :the_state_does_not_matter}
  end

  def handle_events(events, _from, state) do
    # Wait for a second.
    :timer.sleep(1000)

    # Inspect the events.
    IO.inspect(events)

    # We are a consumer, so we would never emit items.
    {:noreply, [], state}
  end
end

{:ok, a} = GenStage.start_link(A, 0)   # starting from zero
{:ok, c} = GenStage.start_link(C, :ok) # state does not matter

GenStage.sync_subscribe(c, to: a)
Process.sleep(:infinity)

I read the doc Process — Elixir v1.20.2, it says with infinity with process will be suspended, what does it mean?

Thanks