Identifying the north and south pole of a magnet can be important if you are using one or more magnets together to attract or repel, yet it is not always straightforward to tell if the magnets are not marked. There are a number of ways you can identify which pole is which on a magnet including using a compass or another magnet. However, by far the easiest and most reliable is to use a pole tester, such as the ones here.
Alternatively, if you want to visualise a magnets magnetic field rather than identify polarity then our iron powder/filings or magnetic field paper are ideal.
