HashSet is a hash-based collection that allows only distinct elements

HashSet.ps1

<# 
  The basics: A HashSet is a collection that holds unique elements in no particular order (O(1) complexity 
  for adding, searching or removing). The HashSet<T> is a generic class in the System.Collections.Generic 
  namespace, ideal for managing large data sets and performing set operations.

  Core aspects: The dotnet HashSet is a hash-based collection that allows only distinct elements. 
  It supports various operations such as Union, Intersection, Difference, and more.
  
  More: https://www.bytehide.com/blog/hashset-csharp
#>

$mySet = New-Object System.Collections.Generic.HashSet[string]