Lamp

A lamp comprising:

• a light source configured to output light into the lamp, wherein the light source is located at a rear side of the lamp;
• a light output part located at a front side of the lamp spaced apart from the light source, and configured to output the light output from the light source after the light is input into the rear side of the lamp by the light source;
• and
• a guide part configured to guide travel of the light output from the light source such that the light travels to the light output part through the guide part, wherein the guide part extends from the rear side of the lamp to the light output part,
• wherein:
• the guide part is divided into a plurality of areas with respect to a forward/rearward direction of the lamp that extends forward from the rear side of the lamp to the front side of the lamp, and
• a width of an area of the guide part located at a front side of the guide part in a leftward/rightward direction of the lamp, within a group of at least some of the plurality of areas of the guide part, is greater than a width of another area of the guide part located at a rear side of the guide part, within the group of at least some of the plurality of areas, in the leftward/rightward direction.