EC2 vs. ECS: Understanding Key Differences Between AWS Cloud ServicesEC2 vs. ECS: Understanding Key Differences Between AWS Cloud Services

If you're new to the world of AWS cloud services, you might assume that there are few major differences between EC2 and ECS. Not only do their names sound similar, but they overlap in functionality in key ways — particularly because ECS workloads can run on top of EC2 infrastructure in some cases.

That said, it would be a mistake to treat EC2 and ECS as identical. As this article explains, they're distinct services that cater to unique use cases.

What Is EC2?

Amazon EC2 — short for Elastic Compute Cloud — is a service in the Amazon Web Services (AWS) cloud that provides access to servers via an infrastructure-as-a-service (IaaS) architecture.

In simpler terms, EC2 is a way to "rent" cloud-based server instances. If you need a server to host a workload and you don't want to buy, set up, and manage your own physical server, you could purchase an EC2 instance and host your workload in the cloud instead.

You may hear folks say that EC2 is a cloud service for accessing virtual servers, since most of the server instance types available through EC2 are virtual machines. However, EC2 offerings also include bare-metal cloud servers, so it's not strictly for VMs.

EC2 debuted in 2006, making it one of the first major services on AWS and one of the first widely used cloud services in general.

What Is ECS?

Amazon Elastic Container Service, or ECS, is a managed container orchestration service in the AWS cloud. Its purpose is to simplify the process of deploying and managing containers across a cluster of servers.

You can also orchestrate containers using solutions like Kubernetes — in fact, AWS offers a separate managed container orchestration service, called Elastic Kubernetes Service (EKS), that does just that.

However, ECS exists alongside EKS because Amazon originally developed ECS in 2014 as a homegrown container orchestrator, before Kubernetes gained massive popularity. Although the vast majority of container-based workloads are now orchestrated using Kubernetes, Amazon continues to offer ECS as an alternative option.

EC2 vs. ECS: Similarities and Differences

At a high level, the similarities between EC2 and ECS are simple enough: Both provide ways to deploy workloads on the AWS cloud. The differences are also straightforward: EC2 is a service for setting up cloud-based servers (on which you can then deploy applications), while ECS is a service for deploying containerized applications.

But those summaries don't do full justice to how EC2 compares to ECS. Let's dive a little deeper.

Similarities Between EC2 and ECS

Beyond the fact that EC2 and ECS are both cloud services that can host workloads, they're also similar in that EC2 server instances are one way of providing the underlying infrastructure that hosts containers on ECS.

To understand fully what that means, you need to understand what are known as ECS "launch types," or ways of deploying containers with ECS. There are two main options:

(Amazon also offers a third ECS launch type, called ECS Anywhere, that lets you deploy containers on your own, on-prem servers as part of a hybrid cloud architecture, but that's not really relevant for understanding the differences between EC2 and ECS.)

If you choose the EC2 launch type for ECS, you end up using EC2 and ECS simultaneously. This is the main way in which EC2 and ECS overlap. Note, however, that this is just one approach; if you choose a Fargate launch type, EC2 is not part of the picture when using ECS.

Differences Between EC2 and ECS

Beyond the option to use EC2 as an ECS launch type, EC2 and ECS are distinct in most other respects. The main differences include:

In general, if your goal is to deploy non-containerized applications, you'll want to use EC2. If you are deploying containers and want to orchestrate them with ECS (as opposed to an alternative orchestrator like Kubernetes), use ECS.