Amazon EC2 Concepts

• Instance

• EBS Volume

• Region

• Availability Zone

• VPC

• Subnet

• Security Group

• Key Pair

• Elastic Network Adapter

Instance

An Amazon EC2 Instance is a virtual server in Amazon's Elastic Compute Cloud (EC2). Amazon EC2 offers a variety of instance types so you can select the CPU, memory, storage, and networking capacity that meets your requirements.

EBS Volume

An Amazon EBS Volume is a virtual disk that can be attached to any Amazon EC2 Instance within the same Availability Zone. Amazon EBS volumes persist independently of the instance lifecycle. This means that deleting an Amazon EC2 Instance does not remove the EBS volumes previously attached to it.

Region

An Amazon EC2 Region is a geographic area where Amazon EC2 Instances are hosted. Multiple Regions are available so you can run your Amazon EC2 Instances in areas that best meet your performance, compliance, or availability needs. Each Region operates independently and is isolated from others.

Availability Zone

An Amazon EC2 Availability Zone is a location within an Amazon EC2 Region. Each Availability Zone is isolated from failures in other Zones, while still being connected to the others in the same Region through low-latency network links.

VPC

A virtual private cloud (VPC) is a virtual network in Amazon EC2. It is dedicated to your AWS account and logically isolated from other networks in the AWS cloud. Similar to a traditional network, you can configure your VPC by selecting IP ranges, creating subnets, configuring routing, gateways, and security settings. After configuration, you can connect your Amazon EC2 Instances to the VPC.

Subnet

A subnet is a range of IP addresses in a VPC. You can assign Amazon EC2 Instances to any subnet you choose. Public subnets provide Internet access, while private subnets do not.

Security Group

A security group is a virtual firewall that controls the traffic for one or more instances. When you create an Amazon EC2 Instance, you can associate one or more security groups with it. Each security group contains rules that allow specific traffic. Changes you make to a security group are applied automatically to all associated instances. When Amazon EC2 evaluates whether to allow traffic to reach an instance, it considers all rules from every associated security group.

Key Pair

Amazon EC2 uses key pairs to encrypt and decrypt login information. A key pair consists of a public key, which encrypts passwords, and a private key, which decrypts them. When creating a new Amazon EC2 Instance, you can generate a new key pair or assign an existing one. To log in, you must provide the corresponding private key.

• Linux instances do not use passwords; you log in using SSH with the private key.

• Windows instances use the key pair to decrypt the Administrator password before connecting via RDP.

Elastic Network Adapter

Elastic Network Adapter (ENA) is a specialized network interface that enables Enhanced Networking on Amazon EC2 Instances. ENA is designed for high throughput, high packet-per-second performance, and consistently low latency. Depending on the instance type, ENA can provide up to 20 Gbit/s of network bandwidth. For more information, refer to the corresponding article on the AWS website.