Like Bash, PowerShell is a shell with strong scripting possibilities. Although I do believe that PowerShell is more in use as a scripting language in script files than as an interactive Shell. But PowerShell is more: it is a task automation and configuration management framework.
Desired State Configuration (DSC) is an important, but lesser known, part of PowerShell that instead of automating scripts in the PowerShell language, provides declarative orchestration in PowerShell.
If you compare it to Ansible, the support for Linux is very limited. But it is very usable for common administration tasks and missing features can be compensated with PowerShell scripts. Microsoft is very focused on getting it on par with the possibilities for Windows Server. At that time, it will be replaced with PowerShell DSC core, a move very similar to what they...
