PowerShell does not enforce a particular layout for a module in most cases, and there is a great deal of variety in the layout of modules on the internet.
An exception to this is script-based DSC resources. Script-based resources must be placed in a DscResources folder, and each resource is implemented as a separate module under that folder. For example:
LocalMachine
| -- DscResources
| | -- LocalMachine
| | -- ComputerDescription.psd1 (Optional)
| | -- ComputerDescription.psm1
| | -- ComputerDescription.schema.mof
| -- LocalMachine.psd1
| -- LocalMachine.psm1
In some cases, a module will only have a root module file and perhaps a manifest. At the other extreme, a module may split every function in the module into a separate file. Other modules fall anywhere in between these two examples. There are advantages to using either of these...
