What Are the Differences Between Containers and VMs?

Virtual machines are multiple guest operating systems based on hardware, which are emulated by a hypervisor. Containers are an application level construct, and emulate multiple virtual environments which share a single kernel.

System Performance

Virtual Machine	In the case of traditional virtualization with virtual machines, each virtual machine has its own full operating system, so when running applications built into virtual machines, memory usage can be higher than necessary and virtual machines can begin to use up resources needed by the host.
Container	Different from traditional, containerized applications share a operating system environment (kernel) so they use fewer resources than full virtual machines and reduce pressure on the host's memory.

Container “Weight”

Virtual Machine	Traditional virtual machines can take up a lot of disk space: they contain a full operating system and associated tools, in addition to whatever application the VM is hosting.
Container	Containers are relatively light: they contain only those libraries and tools needed to make the containerized application run, so they are more compact than virtual machines and start more quickly as well.

Maintenance & Updates

Virtual Machine	When it comes to updating or patching the operating system, traditional machines must be updated one-by-one: each guest OS must be patched separately.
Container	With containers, only the operating system of the container host (the machine hosting the containers) must be updated. This simplifies maintenance significantly.

Alibaba Cloud Elastic Container Instance (ECI) is an agile and secure serverless container instance service. You can easily run containers without managing servers. Also you only pay for the resources that have been consumed by the containers. ECI helps you focus on your business applications instead of managing infrastructure. Learn more about it.