While hypervisors and Containers are similar in a lot of respects, there are some pronounced differences between the two technologies. The most significant difference between hypervisors and Containers is the way they boot up and consume resources.
Hypervisors are of two types – the bare metal works directly on the hardware while the type-two hypervisor works on top of a host operating system. Containers, on the other hand, work on the host kernel itself. Hence, it does not allow the user to create multiple instances of operating systems. Instead, they create containers that act as virtual application environments for the user to work on.
Another notable difference is the number of instances that each technology can create. A hypervisor allows the users to generate multiple instances of complete operating systems. Containers can run multiple applications or multiple instances of a single application. It does this with containers.
When it comes to memory, hypervisors enable users to run multiple instances of complete operating systems. This makes them resource-hungry as memory is used for services and frameworks that will not be used in any way during production. They need dedicated resources for any particular instance among the shared hardware which the hypervisor allocates during boot. Containers, however, do not have any such requirements. One can create as many containers as needed. Based on the application requirement and availability of processing power, the Docker provides it to the containers. What is more, containers remove all unnecessary technologies and services from the environment, thus drastically reducing their resource consumption.
Another major difference between containers and hypervisors is boot time. As containers do not require such resource allocations for creating containers, they can be created quickly to get started. One of the primary reasons why the use of containers is gaining traction is their capability to get started in seconds. In fact, it is not uncommon to have containers created and started in near real-time as the demand for computing resources increases.
In contrast, a hypervisor might take up to a minute to boot the OS and get up and running. Contains can create containers in seconds, and users can get started in no time.
Lastly, we should mention the support for various operating systems. Hypervisors are OS agnostic. In other words, they can run across Windows, Mac, and Linux. Containers, on the other hand, are limited in that all containers share the same kernel. So, if you have a Linux kernel, then all containers running on that machine must be Linux containers as well. Conversely, a Windows kernel would require all containers to be based on Windows. This stands in stark contrast to hypervisors that allow a single machine to run Windows, macOS, and Linux instances side-by-side at the same time.
