How do containers differ from virtual machines?

How do containers differ from virtual machines?

• A. Containers require separate OS kernels.
• B. Containers isolate applications using shared host OS kernels, while VMs run separate OS instances with independent kernels.
• C. VMs rely on shared host kernel.
• D. Containers provide full hardware virtualization.

Answer: (B)

The main concept is how isolation and kernel usage differ between containers and virtual machines. Containers run an application with its dependencies inside a lightweight, isolated environment that uses the host’s operating system kernel. Everything inside the container shares that single host kernel, while the container has its own filesystem and libraries. This shared-kernel setup makes containers fast to start and efficient, but they’re not independent OS instances. Virtual machines, on the other hand, run a complete separate operating system on top of a hypervisor. Each VM includes its own kernel and emulates hardware, providing full OS isolation from other VMs. This is more heavyweight, with more overhead and longer startup, but it gives stronger isolation. So containers isolate applications using the shared host OS kernel, while VMs run separate OS instances with independent kernels. The other statements don’t fit this distinction: containers don’t require separate OS kernels, VMs don’t rely on a shared host kernel, and containers don’t provide full hardware virtualization.

The main concept is how isolation and kernel usage differ between containers and virtual machines. Containers run an application with its dependencies inside a lightweight, isolated environment that uses the host’s operating system kernel. Everything inside the container shares that single host kernel, while the container has its own filesystem and libraries. This shared-kernel setup makes containers fast to start and efficient, but they’re not independent OS instances.

Virtual machines, on the other hand, run a complete separate operating system on top of a hypervisor. Each VM includes its own kernel and emulates hardware, providing full OS isolation from other VMs. This is more heavyweight, with more overhead and longer startup, but it gives stronger isolation.

So containers isolate applications using the shared host OS kernel, while VMs run separate OS instances with independent kernels. The other statements don’t fit this distinction: containers don’t require separate OS kernels, VMs don’t rely on a shared host kernel, and containers don’t provide full hardware virtualization.