AWS also known as Amazon web services, is Amazon’s offering for a cloud service. It was launched internally in 2002 and became public a few years later and is now the largest cloud offering in the business. AWS can be divided into Regions then into availability zones. A region may be multiple locations in the US, Africa, Europe, Asia, etc. AWS stretches across the globe. Picking the region you deploy your application in may not be as easy as you think. You have to keep in mind compliance, there may be different laws on your data depending on where it’s stored. Then there’s latency, if you have users in America and you deploy the application in Asia you might have some unwanted latency. Then there’s price, you have to be aware that different regions may be priced differently. Then finally there’s capability, some services just aren’t available in all regions https://aws.amazon.com/about-aws/global-infrastructure/regional-product-services. Within each region you have a minimum of 3 and a maximum of 6 availability zones. Within these zones you have 1 or more data centers, with redundant power, networking and connectivity. These zones are physically separate from each other so if one suffers a fault or natural disaster the region will be safe. The AZ connect with each other with high speed, low latency links.