This example uses the command-line interface (CLI) instead of the web console. Choosing the CLI over the console is largely a matter of preference, but they both result in the same underlying API calls being made in your account to create resources.

While the key-name argument is optional, you will not be able to connect to your instance unless you have preconfigured some other way of logging in. When the instance is created, the public half of the key is written to ~/.ssh/known_hosts so that, when you use your SSH client with the private key, the instance recognizes you as an authorized user.

Since no Virtual Private Cloud (VPC) or security groups are specified, the instance will be launched in your account's default VPC and security group. You can modify an instance's security groups after it is launched without stopping it.