| Concept | Description | Role | Example |
|---|---|---|---|
| Bash | - A shell program that interprets the commands you type in the command line and executes them on your system. - It’s a command-line interface and a programming language for scripting. | Handles the input from the command line and talks to the kernel to execute your commands | echo "Hello, World!" |
| Shell | A program that interprets and runs text commands, like Bash, Zsh, or Fish. | Provides a command-line interface between the user and the OS. | Bash, Zsh, Fish |
| Terminal & Command line | Terminal - A software program that provides an interface for interacting with the shell using text commands. Command line -The literal text area where you type commands. | Terminal - A window or interface where you can run commands (contains the command line and shell). Command line - The input field where commands are typed and processed by the shell. | Terminal: GNOME Terminal, macOS Terminal |
| kernel | The core part of the operating system that interacts with hardware (CPU, RAM, devices, etc.). | Manages system resources like memory, processes, and hardware interaction. | Linux Kernel, Windows NT Kernel |
- Bash is a shell used to interpret commands.
- The shell is the program that runs in the terminal and executes commands.
- The terminal is where you interact with the shell.
- The command line is just the text-based interface where commands are typed (part of the terminal)
- The kernel handles hardware and low-level system tasks.
General flow
- You open the terminal → The terminal program runs.
- The terminal starts a shell (usually Bash).
- The shell (Bash) displays the command line (prompt) where you can type your command.
- You type a command, like
ls, in the command line. - Bash (the shell) processes the command, sends it to the kernel if necessary (processes system calls and executes it, then gives control back to shell), and receives the result.
- The result is displayed back in the terminal below the command line.