Streaming Replication Setup

So I've been looking at Streaming Replication with a hot standby for PostgreSQL 9.6. Generally speaking seems simple enough.

However, I've been looking at a couple guides, specifically:

https://wiki.postgresql.org/wiki/Streaming_Replicationhttp://www.rassoc.com/gregr/weblog/2013/02/16/zero-to-postgresql-streaming-replication-in-10-mins/

The main difference that I'm wondering about is the below in the first link:

archive_mode = on archive_command = 'cp %p /path_to/archive/%f' 

and the below in the second link:

listen_address = # make sure we're listening as appropriate wal_level = hot_standby max_wal_senders = 3 checkpoint_segments = 8 wal_keep_segments = 8 

Basically, the second link does not make mention of the archive_mode/command.

My question is if this is necessary, and if not what benefit do I gain in having it? Additionally if it is needed, I assume I could specify an SCP, or Rsync command to sync the files?