PostgreSQL: What is data replication?
It means nothing, really. PostgreSQL has a number of replication features, as the relevant chapter in the manual details.

That article is apallingly wrong and outdated. Ignore it. "No referential integrity" in MySQL? Bah.

If you have an account on that site, please ask for it to be removed or fixed or whatever can be done. As it stands it's dangerously misleading and wrong, and has no place claiming to be current accurate information.