A terminal aesthetic is a visual style that borrows from text-based computer terminals: dark screens, monospaced-looking text, prompt marks, and simple status lines. A website may use these details to feel technical or familiar to people who use coding tools.
Think of a page styled like a computer command window, even though it is still an ordinary website you can click and scroll.
The look should not make visitors pretend to type commands they do not understand. Keep normal navigation clear and make sure text is readable on different screens.