title: What is an elastic network interface (ENI) and when would you use it?
body: <p>An elastic network interface is defined as a virtual network interface <a href="https://docs.aws.amazon.com/vpc/latest/userguide/VPC_ElasticNetworkInterfaces.html" rel="noreferrer">https://docs.aws.amazon.com/vpc/latest/userguide/VPC_ElasticNetworkInterfaces.html</a>.</p>
  
  <p>I was wondering what use cases exist of this. Why would not I simply put directly an instance instead of having to use the eni, and attach it to an instance.</p>
  
  <p>Thks!</p>