Street lights, also known as street lamps, are luminous lighting systems on roads, streets, and public squares. They are usually activated and illuminated at night or at dark and extinguished after dawn. The basic function of a streetlight is to illuminate, with the additional function of being a work of art, a landmark, a signpost, a telephone booth, a message board, a letterbox, a meeting place, and advertising lightbox, a smart lamp post, etc. Historically, street lamps were used with gas, torches, candlesticks, lanterns, etc.

Facades, driveways, parks, cycling routes, and highways all require external illumination for a variety of reasons. Lighting, for example, can help with orientation, emphasize activities, promote safety, express characters, or stage events, depending on the situation.
The amount and kind of traffic are the two most important things to consider when it comes to street lighting. These two elements decide whether or not street lighting is required, and if so, what type of illumination is required.
The amount and kind of traffic on a roadway defines which lighting-class it belongs to in public spaces. These lighting classes are determined by municipalities and cities based on street lighting design criteria.
In Northern Europe, each country follows and specifies standard design guidelines. The more lighting classes you have, the more illumination you’ll need. In practice, the lighting level (which ranges from 1 to 6) controls the amount of light required and the uniformity of the light. Lighting levels in congested city centers can be as low as 1 or 2, while on calm streets they might be as high as 5 or 6.