What is the difference between AB and BA.

Answer:
They are technically the same thing
Step-by-step explanation:
Line BA is the same as line AB. Both pass through the same two points A and B. A line-segment may be also a part of ray. In the figure below, a line segment AB has two end points A and B
Answer:
the difference between [tex]\vec{AB}\: and \: \vec{BA}[/tex] is:
[tex]\vec{AB}[/tex] is equal to opposite of [tex]\vec{BA}[/tex]
mathematically:
[tex]\vec{AB}=-\vec{BA}[/tex]