Magnetic poles:

The two regions near the ends of a magnet at which the attracting forces appear to be concentrated are called the magnetic poles.
The pole (when freely suspended) which points towards the earth's geographic north pole is called the North Seeking Pole ‘N' (or north pole for short) and that which points to the south geographic pole, the South Seeking Pole ‘S' (or south pole).

It is observed that two north poles repel each other and likewise with two south poles; however a north pole and a south pole will attract each other. This is summarised in the fundamental law of magnetism:

Like Poles Repel, Unlike Poles Attract

To test a specimen for the presence of magnetism it is necessary to observe repulsion. Attraction simply means that the specimen is magnetic but it may not be magnetised. Thus the test for magnetism is repulsion.