Get-Command

Get basic information about PowerShell commands: cmdlets, files and functions.

Syntax
      Get-Command [[-argumentList] Object[]]
         [-verb string[]] [-noun string[ ]] [-totalCount int]
            [-syntax] [-pSSnapIn string[]] [CommonParameters]

      Get-Command [[-name] string[]] [[-argumentList] Object[]]
         [-commandType {CommandTypes}]  [-totalCount int]
            [-syntax] [CommonParameters]

key
    -name
        Get information for cmdlets (or command elements) with this name.
        All or part of the name, wildcards are permitted.
        
    -verb
        Get information for cmdlet names that include the specified verb.
        "Get", "Set", "Remove" etc.  Wildcards are permitted and multiple
        verbs or verb patterns can be specified: "*et".
        
    -noun
        Get information for cmdlet names that include the specified noun.
        "process", "Service", "Variable" etc. Wildcards are permitted:"*item*"
        
    -commandType 
        Get only specified types of command objects:
             Alias              Powershell Alias
             All                       
             Application        All non-PowerShell files in the PowerShell path.
             Cmdlet             Powershell Cmdlet (default)
             ExternalScript
             Filter             All PowerShell functions
             Functon            All PowerShell functions
             Script
                
        You can use -CommandType or its alias, -Type.
        
    -totalCount 
        Count the number of items retrieved.
        
    -syntax 
        Describe the item:
        alias name, cmdlet syntax, function definition, filter definition,
        script path/filename.
        
    -argumentList
        Get information about a cmdlet when it is used with a specific argument,
        such as a file path or a registry key. e.g., "HKML\Software" or "cert:\my".
        This is useful because some cmdlet parameters are added dynamically.
        
    -pSSnapIn
        Get the cmdlets supported by the specified Windows PowerShell snap-in. 
        For more info, type "get-help about-PSSnapins".

    CommonParameters:
         -Verbose,-Debug,-ErrorAction,-ErrorVariable,-OutVariable.

Examples

Describe the 'Set' verbs:

PS C:\>get-command -verb set | format-list
PS C:\>get-command -verb set | format list *

Display cmdlets in noun-based groups:

PS C:\>get-command | sort-object noun | format-table -group noun

Retrieve information about all the elements available to PowerShell (all files, functions, aliases and cmdlets):

PS C:\>get-command *

Klinger: "Oh, you were built for command. Those shoulders -- broad enough for four stars. That height-- commanders should be tall--to look down on his men"
Corporal: "Napoleon didn't do so bad" - Dialogue from M*A*S*H 1978

Related:

Get-Help - Open the help file
Get-PSDrive - Get drive information (DriveInfo)
Get-Member - Enumerate the properties of an object
Equivalent bash command: man - Display helpful information about commands.