Ambient
The base layer that lets you move around comfortably. Cove strips, panels and wide-beam downlights do this job. It should be even and never the brightest thing in the room.
Task
Light for doing something specific: cooking, reading, getting ready. Under-cabinet profiles, mirror lights and a linear over a desk all count. Put task light close to the job and in front of you, so you do not work in your own shadow.
Accent
Light for looking at things. Narrow spots on art, a wall washed from a track, a strip inside a shelf. Accent light is what gives a room depth, and it should be clearly brighter than the ambient layer around it.
Control ties it together
Put each layer on its own switch or scene. With dimmable and tunable fittings, the same room can be bright and neutral for a busy afternoon and low and warm at night.