Wall Washing is a beautiful effect that can be easily achieved with recess lighting. Wall washing is just that, it bathes the wall in a soft light, to highlight the area, but not be overly bold about it. Where accent light tends to be more specific to a painting or sculpture, wall washing is softer.
For instance, in an office, there might be behind the desk various diplomas and certificates on the wall. Well placed recess lighting can wash the wall in a soft light, that brings attention to those items, but not in a glaring way. Or maybe, on a side wall, there is a bookshelf, loaded with wonderful tidbits of information. Washing that in light provides a beautiful affect while actually helping one to read the spines.
For a more simple example think of a hallway, lighting the walls to enhance the path. Significantly a different look, than that one overhead light, bright as it is, that doesn't quite reach both ends of the hall. Or just bathing a wall in the living room might help to make a smaller room look a little larger. Maybe you have painted an accent wall in your bedroom, and want to bring a little attention to that. Give the room it's own mood, creating a specific atmosphere.
And what if that accent wall is textured?!
By placing the lights a little closer to the wall and a little closer together, you can create shadow, enhancing the textures already present. So an accent wall done in stucco, will stand out even more that it did before. You might consider doing this over your fireplace to enhance the craftsman ship of the brickwork or any number of textured vertical surfaces.
Don't think of walls as just a necessary means to hold up the roof. Let recess lighting help you to use them to make the room stand out.
