KOH is potassium hydroxide.  Since it is composed of the hydroxide anion (OH-), it is a strong base.  In solution, the hydroxide anion will completely react with any available protons, that is why KOH is a strong base.  It is not an acid of any type, weak or strong, since KOH does not contribute any protons to solution.  KOH is a salt since it is composed of inorganic ions and forms a solid in the absence of any solvent.  The two ions (K+ and OH-) completely ionize in water.  So KOH is both a strong base and a salt.