title: In Powershell, what kind of data type is [string[]] and when would you use it?
body: <p>I'm trying to find info about when you would use <code>[string[]]$MyStuff</code>.  Is this an array of characters, or just an array with elements that are explicitly strings, or ...?</p>
  
  <p>I've seen this used in script samples and it's really not clear.  Often I've seen it used for variables that receive output of some non-native utility's text, or as the data type for an input parameter of a function.</p>
  
  <p>What do those extra brackets mean?</p>