You know what Docker is. But what is Docker not? What is the opposite of Docker? There are several ways to think about that question, all of which help to highlight Docker’s wide-ranging relevance.
Following is a list of comparisons that people tend to make when discussing Docker and Docker containers.
Docker vs. Virtual Machines
Probably the most commonly discussed opposite of Docker is virtual machines. You frequently hear people talking about “Docker vs. virtual machines.”
This makes sense. If you think of Docker containers as a building block that you can use to create application infrastructure, then they’re an alternative to virtual machines.
Of course, building application infrastructure is not the sole use case for either virtual machines or Docker. But it is a common one for both.
Docker vs. Serverless
Peoples sometimes discuss Docker as an alternative to serverless computing services, such as AWS Lambda.
I don’t think this comparison makes much sense, because there is little overlap between between serverless computing and Docker containers use cases.
However, given the fact that both Docker and serverless computing are among the most-hyped technologies of the moment, it’s perhaps unavoidable that folks would seek to compare them.
Docker vs. LXC
Docker is only one container framework—and it’s by no means the first one. It is just the most commercially successful.
There are several other frameworks for building containers that serve as alternatives to Docker. LXC is the most popular.
Docker vs. Kubernetes
When you start typing “Docker vs.” into Google, “Docker vs. Kubernetes” is the first autocompleted search result.
That’s surprising. Technologically speaking, Kubernetes and Docker containers don’t compete with each other. Kubernetes is a tool that complements Docker.
From a market or industry perspective, however, this search suggestion makes sense. Docker the company competes with companies that back Kubernetes. But the competition centers around orchestration tools, rather than the core container engine.
Docker vs. Wine
Curiously, “Docker vs. Wine” is also on Google’s autocomplete list for “Docker vs.” searches.
I assume that people performing this search are interested in comparing Docker containers to Wine, the application compatibility layer that allows you to run some Windows applications on Linux.
This is interesting because Docker containers don’t allow you to run Windows applications on Linux at all. Discussions such as “Docker vs. Wine” suggest that there is fundamental confusion among some people about what Docker does.
Clearly, there are many different ways to think about the technologies Docker competes with or serves as an alternative to.
While some of these Docker comparisons make more sense than others, they all underline how much awareness of Docker containers has risen in the four years since Docker’s launch. We now think of Docker not just as an alternative to virtual machines, but to a range of other technologies (and, for that matter, companies) as well.