EC2(Elastic Compute Cloud) - AWS Services in Plain English

What is EC2?

Using this service, you can rent virtual servers from AWS and you'll pay only for the time that you use. If you no longer need the server, you can terminate.

What can you do with the server?

Anything you want. You can use it as web server, database server or application server or any role that you want the server to perform. You've complete control over your virtual server and you can install the software that you need.

Where the server will be located?

As with most of the services of AWS, you can select the region and availability zone at which your server will be hosted. There are multiple regions across the world located in different countries. You can host it 'North Virginia' to 'Mumbai' to 'Sydney'. Based on your requirement, you can get the server from any AWS region.

Can I select the RAM size?

In AWS terms, a server is called as 'an instance'. There are many predefined instance types available in AWS from which you can choose. This may seem like a constraint. But, don't worry. AWS offers a wide range of instances which would satisfy your needs. There are different types of AWS Instances. - General Purpose, Compute Optimized, Memory Optimized, Storage Optimized etc... Based on your needs, you can pick the instance type that you need.

What about security? Can I allow access to specific ports?

Yes. All ports are blocked by default. You can unblock specific ports that you may need through a feature called 'Security Groups'. Security Group is a record which contains 2 pieces of information

• CIDR block from which the port can be accessed
• Actual Port number

What about Operation System and other software?

AWS uses a term AMI(Amazon Machine Image) which refers to the OS and the software bundled together. There are many AMIs available at AWS from which you can choose when creating a server. You can choose from different versions of Linux or if you want, you can choose any supported version of windows operating system. These AMIs which are available at AWS are called 'base images'. You can take the 'base image' and customize it to create a custom AMI based on your needs. You can use this 'Custom AMI' for your future needs.