## TL;DR

Bash (Bourne Again Shell) is the default shell on most Linux distributions. Shell scripts automate tasks: file operations, process management, text processing. Variables, conditionals, loops, functions — a complete programming language for system administration.

## Core Explanation

Variables: `NAME='value'`, reference with `$NAME` or `${NAME}`. Conditionals: `if [ -f file ]; then ... fi`. Loops: `for i in *.txt; do ... done`. Input: `$1 $2 ...` (positional params), `$#` (count), `$@` (all). Exit codes: 0=success, non-zero=failure. `set -euo pipefail` for strict mode (exit on error, undefined variable, pipe failures). Shebang: `#!/bin/bash`.

## Further Reading

- [Bash Reference Manual](undefined)