Overview about VPC :

A virtual private cloud ( VPC ) is a virtual network that closely resembles a traditional network that you’d operate in your own data center, with the benefits of listing the scalable infrastructure of Amazon Web Services ( AWS) . After you complete the tasks in this exercise, you’ll have an

Amazon EC2 instance running in a VPC that you can access from the Internet using SSH ( for Linux instances) or Remote Desktop ( for Windows instances).

The following diagram shows the architecture that you’ll create as you complete the exercise in this guide. The security group that you set up and associate with the instance allows

Traffic only through specific ports, locking down communication with the instances according to the rules that you specify. Using an Elastic IP address (EIP) enables an instances in a VPC, which is otherwise private , to be reaches from the internet through an internet gateway ( for example, it could act as a web server).

If you created your AWS account after 2013-12-04, it supports only EC2-VPC.In this case , you’ll have a default VPC in  each AWS region. A default VPC is ready for you to use - you can immediately start launching instances into your default VPC without having to perform any additional configuration steps. A default VPC combines the benefits of the advanced networking features provided by the EC2- VPC platform with the ease of use of the EC2-Classic platform.

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