The qibla or kiblah is the direction towards the Kaaba in Mecca. This direction is used by Muslims in various contexts.
In particular, it is the direction of prayer for the salah.
Most mosques contain a mihrab (a wall niche) that shows the direction of the qibla.
The qibla is also the direction to avoid when relieving oneself or spitting. The dead are also buried facing this direction.
Text adapted from English Wikipedia, Creative Commons Attribution-ShareAlike License 4.0.
Qiblah Compass for finding the direction of Mecca using a magnetic needle, Khalili Collection: Hajj and the Arts of Pilgrimage SCI 471