What is the difference between Alibaba Cloud Region, Zones, Location and Towns?

How can an Alibaba Cloud newbie differentiate between regions, zones, locations, towns where and data centers?

Also, can a zone determine the products offered by Alibaba Cloud and what are the implications in regards to local intranet communication when deploying services across different zones especially when it comes to high availability technologies(e.g. load balancing and database redundancy).

I hope somebody can clear the air because these terms seem a bit confusing to new Alibaba Clouders.