TUI
also: Text User Interface, Terminal UI, Text-based UI
A Text User Interface (TUI) is a graphical interface displayed in the terminal using text characters and keyboard navigation, offering a middle ground between command-line and GUI applications.
A TUI allows users to interact with applications through menus, buttons, and input fields rendered entirely in the terminal using ASCII or Unicode characters. Unlike command-line interfaces that require typed commands, TUIs provide visual organization and mouse support (in compatible terminals), making them more intuitive while remaining lightweight.
Common examples include htop (system monitoring), nmtui (network configuration), and midnight commander (file manager). TUIs are particularly useful on remote servers accessed via SSH where running a full GUI is impractical.
TUI applications typically use libraries like ncurses or curses to draw formatted text layouts, manage colors, and handle keyboard input, allowing them to function reliably across different terminal emulators.