The position of a place north or south of the equator is described in terms of its latitude. Since we're talking about the surface of a sphere, latitude is an angle, and its value is given in angle measure.
Any unit of angle is fine ... degrees, radians, grads, etc., and if you're given an angle in one unit, you can always easily change it to a unit that you like better ... but 'degrees' has been the unit used most often for latitude, and longitude too, practically since the whole system was invented a few hundred years ago.
For parts of an angle smaller than a whole degree, 1/60 of a degree (minutes) and 1/3600 of a degree (seconds) were used traditionally for the first couple hundred years. But that ponderous, inconvenient system is rapidly giving way now to plain old decimal degrees, probably because those are easier for the computer to handle.