Containers vs virtual machines in Docker - Quick Revision & Key Differences

Recall & Review

beginner

What is a container in simple terms?

A container is like a small, portable box that holds an app and everything it needs to run, sharing the computer's main system but staying separate from other apps.

beginner

How does a virtual machine (VM) differ from a container?

A VM is like a whole computer inside your computer, with its own operating system, while a container shares the main operating system but keeps apps isolated.

intermediate

Why are containers usually faster to start than virtual machines?

Containers start faster because they share the main operating system and don't need to boot a full separate system like VMs do.

intermediate

What is one main advantage of virtual machines over containers?

Virtual machines provide stronger isolation because each VM runs a full operating system, making them better for running different OS types or very secure environments.

intermediate

Can containers run different operating systems than the host machine?

No, containers share the host's operating system kernel, so they cannot run a different OS than the host, unlike virtual machines which can.

What do containers share with the host system?

A The entire operating system

B The operating system kernel

C Hardware only

D Nothing, they are fully separate

Containers share the host's operating system kernel but keep applications isolated.

Which technology boots a full operating system inside your computer?

A Virtual machine

B Container

C Docker image

D Kubernetes pod

Virtual machines boot a full operating system, unlike containers.

Why might you choose a virtual machine over a container?

A For faster startup times

B To save disk space

C To run a different operating system than the host

D Because they share the host OS kernel

Virtual machines can run different operating systems than the host, containers cannot.

Which is generally more lightweight and uses fewer resources?

A Containers

B Virtual machines

C Both use the same resources

D Neither, they are the same

Containers are more lightweight because they share the host OS kernel.

What is a key security difference between containers and virtual machines?

A Containers have stronger isolation

B Neither provides isolation

C Both have the same isolation level

D Virtual machines have stronger isolation

Virtual machines provide stronger isolation by running separate OS instances.

Explain the main differences between containers and virtual machines in simple terms.

Think about how each runs apps and uses the computer's system.

Describe a situation where you would prefer using a virtual machine instead of a container.

Consider when full separation from the host system is important.