Variables can be created to hold on to information that's to be reused in a function or a script. A variable may be a simple name, or loaded from a file.

The * variable commands are available to interact with variables beyond changing the value, such as setting a description, making a variable in a specific scope, or making a variable private.

A variable scope affects how variables may be accessed. Variables are created in the local scope by default.

Arrays are sets of objects of the same type. Arrays are immutable, and the size of an array cannot change after creation. Adding or removing elements from an array requires the creation of a new array.

Hashtables are associative arrays. An element in a hashtable is accessed using a unique key.

Lists, stacks, queues, and dictionaries are advanced collections that may be used when a particular behavior is required, or if they offer a desirable performance benefit.

In Chapter 6, Branching and Looping, we will explore branching and looping in PowerShell.