Learn how to declare variables, manipulate variables, and call special variables.
Learn about the naming conventions used in variables, how to assign values and unset them.
Learn how to find the length of a variable, make variables read-only, make variables persist to subshells, and unset variables from their values.
Learn how to handle cases when your variables aren't set with expansion operators.
Learn about the positional parameters used in the shell that denote arguments, number of arguments and script name. Also learn about special characters.