Add, Update and install WSP in SharePoint using PowerShell Script

Add WSP using the following power shell script
$wspname="C:\\name.wsp"
Add-SPSolution -Identity wspname

Upgrade a WSP using the following power shell script.

(Update-SPSolution -Identity wspname -LiteralPath Physicalpath -GACDeployment)

Update-SPSolution -Identity ListDefinition.wsp -LiteralPath 

C:\\name.wsp -GACDeployment 

Install the newly created Feature using powershell script.

(Install-SPFeature FeatureFolderName)

Install-SPFeature "ListDefinition_New_List_Feature"