===Using Variables in Shell Scripts===
'''Definition'''
''<b>Variables</b> are used to '''store information''' to be referenced and manipulated in a computer program.<br>They also provide a way of labeling data with a descriptive name, so our programs can be understood<br>more clearly by the reader and ourselves.''<br>Reference: https://launchschool.com/books/ruby/read/variables
Refer to the diagram to the right for examples using positional and special parameters.
=== Command Substitution / Math Operations ===
