Starting with PowerShell version 2.0, developers can create PowerShell modules. PowerShell modules encapsulate a set of common functionality. For example, there are vendor-specific PowerShell modules that manage various cloud services. There are also generic PowerShell modules that interact with social media services, and perform common programming tasks, such as Base64 encoding, working with Named Pipes, and more.
Modules can expose command aliases, functions, variables, classes, and more.