Amazon Elastic Cloud Compute (EC2)

An Amazon EC2 instance runs on a host machine within a specific AWS Availability Zone, providing virtualized access to underlying host machine resources.
Some Instances offer Bare-Metal Access which provides application with direct access to the processor and memory resources of the underlying server
Instance Types - Rated for a certain level of network throughput

Amazon Machine Image provides...
- A template for OS and applications on the root volume of an instance
- A block device mapping that can specify additional volumes to mount when an instance launches
Each AWS region maintains its own listing of AMIs
- Any AMIs created are available only within a specific region unless copied over

Virtual network interfaces called Elastic Network Interface provide networking for your Amazon EC2 instances
Each EC2 instance is assigned a Primary Network Interface that is associated with a subnet within an Amazon VPC
- Instances are assigned one of subnets within the default VPC
- Instances receive
  - a private IP address to communicate with instances inside the Amazon VPC
  - a public IP address to communicate with a internet
Security Group rules must be set up to allow connection
- Acts as stateful firewall, protecting the traffic entering and exiting the network interface
Additional Network Interfaces may be attached, each with its own MAC address and IP address
- Secondary Interfaces may be detached from one instance and attached to another
Number of network interfaces attached doesn't affect the network throughput

Accessing Instances