Beforehand, sorry for my english...
The || - is short version of |.
I.e. if you have simple condition like this:
(a||b) then, there is no difference, what operator to use. In case with complex condition:
((a==b)||(c==d)||(e==f)) will be difference. The || operator will be checking the conditions, untill it find TRUE. If it happened on (a==b), the other conditions will not be checked. If you are choose the | operator, then all conditions will be checked necessarily.