All Chinese characters have a radical or are a radial in it self. There are 214 radicals today but some of them are under debate to be removed. Look at the number 38
to the left, it is the character for "woman". it is also the radical for many female things:
sister, mamma etc.
radicals is used to tell something about the meaning of the character, e.g. made of metal, is tall etc. it is also used to look up a character in a dictionary. to find a character you look for the radical in a radical list. when you have found your radical you count the remaining number of strokes in the character. with this information it is now possible to find the character.