You’ve got ambient, task, accent, and decorative. Ambient lighting is your base layer—the overhead fixtures, recessed cans, or wall sconces that fill a room with general illumination so you can walk around safely. Task lighting is exactly what it sounds like: a desk lamp, under-cabinet kitchen lights, or a reading lamp next to a chair, aimed at a specific work surface. Accent lighting is used to draw the eye—picture track lights hitting a painting, or a well-placed uplight washing a brick wall. Decorative lighting is the chandelier over the dining table or the string lights on a patio; its main job is to look good, though it often contributes some ambient light too.
A lot of people mix these up or try to cover everything with one ceiling fixture. That’s why so many rooms feel either like a doctor’s office or a cave. A well-lit room uses at least three of these in combination. For example, in a living room: recessed cans (ambient) for general light, a floor lamp next to the sofa (task) for reading, and picture lights (accent) to highlight art. Decorative might be a pendant over the coffee table just for style. Skip the accent layer and the room feels flat. Skip task lighting and you’ll find yourself squinting over a book. Get all four working together and you won’t think about lighting at all—it’ll just feel right.