Sombrilla vs. parasol vs. quitasol

The Spanish language has a few different words to describe an object that provides shelter from the sun, namely: 'sombrilla', 'parasol', and 'quitasol'. Although in some contexts these words can be used interchangeably as they all refer to items designed to block the sun, they do have subtle differences pertaining to their usage and context.

Sombrilla

The word 'sombrilla' is most commonly used and is a generic term for an object that provides shade, typically from the sun. It's often associated more directly with personal use, like a beach umbrella.
La sombrilla en la playa protege del sol.
(The beach umbrella provides protection from the sun.)
No olvides llevar la sombrilla al picnic de mañana.
(Don't forget to bring the umbrella for tomorrow's picnic.)

Parasol

'Parasol' is generally synonymous with 'sombrilla', but it tends to have a more formal or elegant connotation, as well as being associated with architectural sun protection features.
El edificio tiene un gran parasol que da sombra a la terraza.
(The building has a large parasol that shades the terrace.)
El restaurante ha instalado nuevos parasoles para sus clientes en el patio.
(The restaurant has installed new parasols for its customers on the patio.)

Quitasol

'Quitasol' is a less commonly used word and usually refers to smaller, personal sunshades. The word 'quitasol' literally translates to 'take away sun'. Generally used in some South American countries.
Mamá, ¿puedes pasarme mi quitasol?
(Mom, can you pass me my sunshade?)
La señora llevaba un pequeño quitasol para protegerse del sol intenso.
(The lady was carrying a small sunshade to protect herself from the intense sun.)

Summary

'Sombrilla', 'parasol', and 'quitasol' are Spanish words that all refer to objects providing shade from the sun. Generally, 'sombrilla' is associated with personal use like beach umbrellas, 'parasol' carries a slightly formal or elegant connotation or is used to denote architectural features, and 'quitasol' is used less frequently and refers to smaller personal sunshades.