What Is An EC2 Instance And How Does It Work?By Pralhad Barhate / May 31, 2025 What Is an EC2 Instance? An EC2 instance is:A resizable virtual machine in the cloud.Used to run applications, host websites, process data, or support backend infrastructure.Scalable: You can increase or decrease resources like CPU, RAM, and storage as needed. Think of it as renting a computer in a data center that you can use as if it were your own.