‘Antiparallel’ means parallel but pointing in opposite directions, like so: ↑↓
Whereas ‘perpendicular’ means pointing at right angles: ↑→
(And, of course, ‘parallel’ without qualification would mean pointing in the same direction: ↑↑)
Whereas ‘perpendicular’ means pointing at right angles: ↑→
(And, of course, ‘parallel’ without qualification would mean pointing in the same direction: ↑↑)
But if those two cars were traveling the same direction, in the same two lanes, they would be properly described as following a parallel path.
from a line vs ray perspective parallel and opposite are equivalent, but when they are rays and not lines, directionality matters.
From a physicist working with spins point of view: yes, parallel has the same direction and antiparallel the oposite.
Each area create their own jargon. Sometimes it's confusing to ousiders and when you pick a book from another area you must double check that the worlds mean what you think their mean.