# Event (relativity)

Upon choosing a frame of reference, one can assign coordinates to the event: three spatial coordinates ${\displaystyle {\vec {x}}=(x,y,z)}$ to describe the location and one time coordinate ${\displaystyle t}$ to specify the moment at which the event occurs. These four coordinates ${\displaystyle ({\vec {x}},t)}$ together form a four-vector associated to the event.