1. It lets a function behave like a compiled cmdlet, thus giving it access to common parameters, such as Verbose and ErrorAction
2. ParameterSetName
3. One from: SYNOPSIS, DESCRIPTION, PARAMETER, EXAMPLE, NOTES
4. Using signed code in RemoteSigned and AllSigned mode will not trigger the execution policy
5. Manifest (psd1) and script module (psm1)
6. PowerShell examines $env:PSModulePath for valid folder structures containing module files and then imports all exported cmdlets, functions, variables, aliases, and so on
7. Source control system
8. To more easily revert changes and have a more granular history of changes
9. To develop code independently from others
10. Static code analysis, for example, proper indentation, style, disallowed aliases, and more