FactorFull is an option of Factor2 (default False). If set to False, products like (a-b) (a+b) will be replaced by a^2-b^2.
Factor2[(a - b) (a + b) (c + d) (c - d)]\left(a^2-b^2\right) \left(c^2-d^2\right)
Factor2[(a - b) (a + b) (c + d) (c - d), FactorFull -> True](a-b) (a+b) (c-d) (c+d)