Bash, a Unix shell and programming language, utilizes variables similar to other programming languages, encompassing local, special, and environmental variables. Local variables exist only within the current session, while exported variables can be passed to child processes, effectively becoming global environmental variables. Bash supports arrays, including associative arrays, though these are less commonly used due to compatibility issues with versions like macOS's Bash 3.2. Bash scripts can manipulate variables, including command-line arguments, using built-in variables such as $@ for argument arrays and $? for exit codes. Environmental variables, typically uppercase by convention, can persist across sessions if added to the .bashrc file. The article highlights Earthly, a tool designed to facilitate reproducible builds for Bash scripts, and emphasizes its utility in managing Bash's variable quirks.