Arithmetic - Accumulator activities on whole memory units.
  Integer, Float,  and other in more advanced cpus.

  Add, Subtract, (Multiply, Divide on advanced cpus)
    Affects Carry, Zero, Overflow flags. 

Boolean - often a subcategory of arithmetic.
  Boolean - performs logical instructions on bits of storage unit.
      
  ALU used provide bit manipulation on whole memory unit.
    AND - 11110111 AND data will force only bit 4 off.

    OR - 00001000 OR data will force only bit 4 on.

    XOR - 11111111 XOR (EOR) data will essentially generate the 1's
      complement of the data.

  Result of boolean action stored.

  May affect fewer flags than arithmetic and uses different rules.