A Redstone Lamp is a block visually resembling Glowstone (hence its crafting materials) that gives off light as long as it is powered. While powered, they have a luminescence like a torch and the same light level as glowstone. They require constant input in order to emit light (making them somewhat inefficient) from a redstone current. Similarly to other light emitting blocks, they will melt snow and ice.
Redstone Lamps are Redstone-related Blocks that were added in Update 0.13.0. When on they provide a light level of 15. They are gold in color when switched on, but brown when switched off.