While it's been a part of the open source world for quite some time, many administrators got their first exposure to Docker containers when Microsoft introduced support in Windows Server 2016. The move signals that Windows Server administrators should gain proficiency in Windows containers.
Containers provide application portability. They have the added benefit of using fewer server resources compared to traditional virtual machines, thanks to sharing a single host operating system.
Because Docker containers started on Linux, this form of virtualization may be new to most Windows Server administrators, making it in their best interest to learn Docker skills such as how to create Windows containers and what tools are available to manage them.
More importantly, containers are widely used on Linux systems and in public cloud platforms. Since many modern enterprises use a combination of resources on premises and in the public cloud, and on Windows and Linux platforms, consider developing Docker skills even if you never start a Windows container.