[GENERAL] Needing verification on instructions for streaming replication

I'm trying to setup streaming replication on a cluster of postgresql databases and I followed the instructions outlined here (https://wiki.postgresql.org/wiki/Streaming_Replication) but I'm stuck on the archive and restore commands. In reading the comments from the archive command, WAL archiving needs a shared directory between the primary and standby machines in order to replicate. Is this something actually required? If so, does postgresql have any recommendations on where this shared directory ought to be hosted?

Thanks,