What is the difference between + 2 ( plus or minus 2 )and minus or plus 2 ?

basically both r same but the difference arises when we multiply , say

(+a) and (+  a)  we get  + a²  but  [since (+) x (+) = + (up) &  (-) x(+) = -  (down)]

(-a) and  (+  a)  we get  minus or  + a²  [(-) x (+) = -  (up) &  (-) x (-) = +  (down)]