Amazon Web Services provides a unified environment where cloud computing infrastructure, platform, and software services can be consumed by the end user. It enables us to be able to build an application by utilizing any combination of the AWS services on offer.

In this chapter, we learned how easy it is to create an AWS account and started using those services to build complex and powerful applications before making them available on the internet or on our internal network by using a VPN or Direct Connect uplink. AWS is a great environment when ease of management, the ability to provision quickly and globally, and financial constraints require us to build compute capacity from operating expenditures.

Although it is fairly simple to build applications on AWS, there are several challenges when using cloud computing systems as a standalone solution or as a hybrid model with an on-premises data center. First, there is the security concern, as we lose control of part of the system by delegating that control to the cloud provider. We looked at the shared security model and how it applies across infrastructure and platform as a service. Along with security, there is a real challenge to provide high availability, as some services within the cloud do not offer any intrinsic high availability, resilience, or backups. Because of this, we need to understand how to make each service highly available and build resilience and backups into our application.

We then took a quick glance at AWS regions, availability zones, and data centers to get a better overview of how AWS has designed its infrastructure to support the high availability of services. As we continue with this book, part of each chapter will also focus on making our services highly available and resilient.