There are multiple definitions of the word 'container'. In the case of Borg, 'container' referred to the kernel resource isolation component, which is completel

There are multiple definitions of the word 'container'. In the case of Borg, 'container' referred to the kernel resource isolation component, which is completely orthogonal to how the apps were packaged. Borg aggressively shared packages between jobs on the machine where possible. Being able to strictly apportion resources between the different jobs on a machine (and decide who gets starved in the event that the scheduler has overcommitted the machine) means you can squeeze more out of a given server (by safely getting its utilization closer to 100%) There are other definitions of the word 'container' that are closer to 'virtual machine' and include things like a disk image which is much harder to share, but that's not what's being discussed in the context of Borg. (Not sure about Kubernetes, that's after my time)