Ma'anar ƙamus na kalmar "haruffa" ita ce tsara ko tsara abubuwa, kamar kalmomi, sunaye, ko lakabi, a cikin jerin haruffa bisa ga haruffan haruffa. Wannan yawanci ya ƙunshi rarraba abubuwa daga A zuwa Z, ko daga Z zuwa A, bisa harafin farko na kowane abu. Ana amfani da haruffan haruffa sau da yawa don taimakawa gano takamaiman bayani cikin sauri, kuma ana amfani da shi a cikin mahallin kamar fihirisa, kundayen adireshi, littattafan littattafai, da ƙamus.