Why Containers?

Every application needs the same three things to run: an OS, the right runtime versions, and its dependencies exactly as it was built against. Get any of those slightly wrong on a new machine and "works on my laptop" turns into a support ticket.

A container packages an app together with everything it needs — down to the exact library versions — into a single, portable unit. Unlike a virtual machine, a container doesn't bundle its own operating system; it shares the host machine's kernel and only isolates the process, filesystem, and network it needs. That's why a container image is typically megabytes, not gigabytes, and why a container starts in under a second instead of the minute or more a VM takes to boot.

By the end of this course you'll be able to package, run, and ship any app this way — starting with what "container" actually means at the OS level.