Graphics
What people actually mean by graphics in games, and the elements that decide whether a game looks good.
Graphics is the catch-all word for everything you see on screen and everything the hardware does to produce it. In practice people use it to mean two different things: the technical quality of the image, and the artistic style of the game. They are not the same, and confusing them explains a lot of arguments.
The technical side
Resolution — how many pixels make up the image, and therefore how sharp it is.
Frame rate — how many images are drawn per second, which decides how smooth motion looks and how responsive the game feels.
Textures — the surface detail on objects. Higher-resolution textures make a wall look like brick rather than a blurry brown surface.
Lighting and shadows — usually the largest single factor in whether a scene looks convincing, and where ray tracing makes its difference.
Effects — reflections, smoke, water, particles, depth of field.
Draw distance — how far away objects remain visible before they fade out or simplify.
What makes game graphics look better?
On a console, most of this is decided for you by the developer, and your choice is usually between a Quality mode and a Performance mode. What you can control is the screen: a good HDR television with Game Mode on, correct calibration and full HDMI bandwidth enabled will improve how a game looks far more than any console setting.
On PC you control each setting individually. The ones with the largest visual impact per unit of performance are usually textures (cheap if you have enough video memory) and lighting quality. Shadow quality and effects density cost the most for the least visible gain — they are the first things to lower when you need performance.
Art direction beats technology
Worth saying plainly: games from ten years ago with strong art direction often look better today than technically superior games with none. Resolution and effects age; a coherent visual style does not. When people say a game "looks amazing", they usually mean the art, not the pixel count.