Instances have nginx installed in them as extra and they are accessible over an ELB.
The example launches a web server, installs nginx, creates an ELB for instance. It also creates security groups for the ELB and EC2 instance.
To run, configure your AWS provider as described in https://www.terraform.io/docs/providers/aws/index.html
Run this example using:
terraform apply
Wait a couple of minutes for the EC2 userdata to install nginx, and then type the ELB DNS Name from outputs in your browser and see the nginx welcome page