Deck and Step Landscape Lighting
Basic deck lighting will attach to the railing of a deck or to the wall of the house adjoining the deck. Step lighting, similarly, will attach to the vertical portion of steps to provide enough light for travelers to see where they're going. As such, this lighting tends to be flat so it can stay out the way, and durable in case it does get kicked or bumped. Still, it helps to have a high impact polycarbonate lens that can withstand a fair amount of punishment.
One simple approach is a light with a rectangular aluminum face plate. The face place will be hooded to direct the light downward and to protect the glass inside. These can be installed fairly flush against wall, railing, or step. A variation on this theme does away with the grating and simply recesses the face plate to minimize the danger. Another variation uses a synthetic brick in place of the aluminum.
These kinds of lights can also be round rather than rectangular, again with or without the face plate. The simplest version simply has a round aluminum frame encircling a round plastic face. For added protection, a grating can be had on these as well. Or the light can come with a hood that juts out slightly. The hood can be a simple visor or an entire quarter sphere encasing the top half of the light. Either way has the advantage of protecting the light a bit from bumps and of protecting you from the flare. The hood directs the light downward where it's useful.
Other deck lights are nothing but hood. They jut out slightly from the railing as small boxes, semi-circles, half umbrellas, scalloped shells, etc. These lights tend to be quite small. This helps them stay out of the way and it makes sure they aren't wider than the railing you attach them to. Even so, these kinds of lights are probably not durable enough for use with steps.
You can also find miniature spotlights small enough to attach to the deck railing. Some can be bolted to the side of the railing and directed from there. Others can be bolted firmly to the underside of the top or bottom rail. These come in especially handy when you need to angle the lighting to get at a dark corner where it would be inconvenient to have the light directly above. The lighting can also be angled to reach a little farther toward the center of the deck rather than simply creating a pool of light at the perimeter. These miniature spotlights can be found as basic cylinders, or shaped as bells for a more artistic look.