Elastic Compute Cloud (AWS EC2)

EC2 provisions and configures virtual machines (VMs) called instances. Instances are essentially just computers, and they can do anything a computer can do. In your technical infrastructure, they are the workhorses that sit and run your code 24 hours a day.

EC2 is more than just instances, however. It also includes a handful of services that manage those instances. Since instances are so general-purpose, there are many configuration options available. These include operating system, performance/price tradeoffs, and Security Groups.

When you launch a new instance, you must set values for these options. If you plan to have multiple instances doing the same thing, you can create a Launch Configuration which can then be used to create multiple identical instances. Furthermore, an Auto Scaling Group can automatically create more instances if the load on your system increases.

Each instance receives an IP address, which can be used to connect to it. When scaling out a system, there will be multiple instances, each with different IP addresses. An Elastic Load Balancer distributes requests to a single IP address across multiple instances.

Let's walk through each of these features in a little more detail and set them up.