Farola vs. poste de luz
While both farola and poste de luz can translate to "streetlight" in English, they emphasize different aspects of the object. Farola tends to refer to the lighting fixture found in urban settings or parks (often decorative), whereas poste de luz explicitly describes the physical pole or column supporting the light, sometimes including utility poles carrying cables.
Farola
A2A farola specifically refers to a street lamp used for public lighting in cities, gardens, and promenades. The word suggests a complete lighting fixture, often with an aesthetic or decorative component intended for pedestrians.
La luz de la farola iluminaba el banco del parque.
(The light from the street lamp illuminated the park bench.)
Cuando oscurece, las farolas de la avenida se encienden automáticamente.
(When it gets dark, the avenue's streetlights turn on automatically.)
El diseño de esa farola es muy antiguo y elegante.
(The design of that street lamp is very old and elegant.)
Un pájaro hizo su nido encima de la farola.
(A bird made its nest on top of the street lamp.)
Poste de luz
B1A poste de luz translates literally to "light post." This term emphasizes the structural column (made of concrete, wood, or metal) that supports the light. It is often used for highway lighting or utilitarian poles that may also carry electrical or telephone wires.
El coche perdió el control y chocó contra un poste de luz.
(The car lost control and crashed into a light post.)
Los técnicos están reparando los cables en el poste de luz.
(The technicians are repairing the cables on the utility pole.)
Pegaron carteles de un perro perdido en cada poste de luz de la calle.
(They stuck lost dog posters on every light post on the street.)
Ese poste de luz de madera parece que se va a caer.
(That wooden light post looks like it is going to fall over.)
Summary
Use farola when describing street lighting as urban furniture, typically within a city or park context where the focus is on the lamp itself. Use poste de luz when referring to the physical vertical structure, utilitarian highway lighting, or poles that support cables in addition to a light source.