Brújula vs. compás
The Spanish words 'brújula' and 'compás' can both be translated to the English word 'compass', however, they refer to different types of compasses and are used in different contexts.
Brújula
In Spanish, 'brújula' refers to a magnetic compass which is a device used for navigation and orientation that shows direction relative to the cardinal directions (north, south, east and west).
Usamos una brújula para encontrar el camino en el bosque.
(We used a compass to find our way in the forest.)
La aguja de la brújula señala hacia el norte.
(The needle of the compass points north.)
Compás
However, 'compás' generally refers to a pair of compasses, an instrument used for drawing circles or arcs.
Utilicé un compás para dibujar un círculo perfecto.
(I used a compass to draw a perfect circle.)
El arquitecto usó un compás para dibujar el plano de la casa.
(The architect used a compass to draw the house plan.)
Summary
'Brújula' and 'compás', while both translating to 'compass' in English, represent different tools in Spanish. A 'brújula' is a navigational tool used to find direction, while a 'compás' is a drafting tool utilized mainly in geometry to draw circles or arcs.