A software container packages an application together with its libraries and dependencies so it runs the same way across different environments, and it shares the host operating system's kernel, which makes it lighter and faster to start than a full virtual machine.
A container runs as an isolated process on the host, using operating-system features to get its own view of the filesystem, network, and processes. Because it shares the host kernel rather than booting its own operating system, it starts quickly and uses fewer resources.
A virtual machine includes a full guest operating system running on virtualized hardware, while a container shares the host kernel and packages only the application and its dependencies. This makes containers smaller and faster to start, though virtual machines give stronger isolation.
A container image is a read-only template that contains the application and everything it needs to run. You start a container from an image, and the same image produces the same container on any compatible host.
Containers package the application and its dependencies but share the host's kernel, so they do not include a full separate operating system the way a virtual machine does.
An image is the read-only template; a container is a running instance started from that image.
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