AWS EC2 Instance - Is it a single virtual image or single physical machine?

Question

Sorry, I had a few basic questions. I'm planning to use an AWS EC2 instance.

1) Is an EC2 instance a single virtual machine image or is it a
single physical machine? Documentation from Amazon states that it is
a "virtual server", but I wanted to clarify if it is an image
embedded inside one server or if it is an single physical server
itself.

2) Is an Elastic Load Balancer a single EC2 instance that handles
all requests from all users and simply forwards the request to the
least loaded EC2 instances?

3) When Auto-Scaling is enabled for an EC2 instance, does it simply
exactly replicate the original EC2 instance when it needs to scale
up?

Answer 1

1. It is a virtual server, a VM, as stated in the documentation.
2. It's a little more complicated that that, based on the way AWS might scale the load balancer, or create a version in each availability zone, etc. It also provides more features such as auto-scaling integration, health checks, SSL termination. I suggest you read the documentation.
3. It uses a machine image that you specify when you create the auto-scaling group (when you create the Launch Configuration used by the Auto-scaling group to be more precise). A common practice is to configure a machine image that will download any updates and launch the latest version of your application on startup.

You might also be interested in Elastic Beanstalk which is a PaaS that manages much of the AWS infrastructure for you. There are also third-party PaaS offerings such as OpenShift and Heroku that also manage AWS resources for you.