Another cool automatic variable, PSBoundParameters, gives you access to all parameters that were bound in your cmdlet or function. Do you remember the variable $args from before? This is $args on steroids. With it being a dictionary, we can access all bound parameters by their name; manipulate, add, and remove keys; and use this variable for splatting, as you can see in the following code sample:

# Another cool dictionary to use
function Get-AllTheThings
{
    [CmdletBinding()]
    param
    (
        $Parameter1,

        $Parameter2
    )

    $PSBoundParameters | Out-Host
    Get-AllTheInternalThings @PSBoundParameters
}

function Get-AllTheInternalThings
{
    [CmdletBinding()]
    param
    (
        $Parameter1,

        $Parameter2
    )

    Write-Verbose -Message 'Pretty cool, eh?'
    Write-Host "Parameter1 was $Parameter1 and Parameter2 was $Parameter2"
}

# Calling Get-AllTheThings will pass all possible parameters
# on to Get-AllTheInternalThings.
Get-AllTheThings -Parameter1 1 -Parameter2 2 -Verbose

# Be careful: If parameters do not exist, you still get errors
function Get-AllTheInternalThings
{
     # Leave the parameter binding and all parameter attributes, and the bound
     # parameters will not throw an error ;)
    [CmdletBinding()]
    param
    (
        $Parameter1
    )
}
Get-AllTheThings -Parameter1 1 -Parameter2 2 -Verbose # Throws now...

We commonly use the bound parameters in scenarios where we write adapters or wrappers around functions. Take a look at the following abbreviated code sample from https://github.com/AutomatedLab/AutomatedLab.Common where this exact technique is used in the New-TfsAgentQueue cmdlet calling Get-TfsAgentQueue internally, using PSBoundParameters like you can see in the following code sample:

function New-TfsAgentQueue
{
    
    param
    (
        [Parameter(Mandatory)]
        [string]
        $InstanceName,

        [Parameter()]
        [string]
        $CollectionName = 'DefaultCollection',

        [ValidateRange(1, 65535)]
        [uint32]
        $Port,

        [string]
        $ApiVersion = '3.0-preview.1',

        [Parameter(Mandatory)]
        [string]
        $ProjectName,

        [switch]
        $UseSsl,

        [string]
        $QueueName,

        [Parameter(Mandatory, ParameterSetName = 'Cred')]
        [pscredential]
        $Credential,
        
        [Parameter(Mandatory, ParameterSetName = 'Pat')]
        [string]
        $PersonalAccessToken
    )

    $existingQueue = Get-TfsAgentQueue @PSBoundParameters
    if ($existingQueue) { return $existingQueue }
    
    # Things happen.
}