srestha link is good but there is no conclusion at last . i.e . we dont which one agree to which one if question comes in paper
1) WALK i read that in this edges and vertices may repeat.
but i did one question in which they said edges dont repeat.
2) now path no edges and vertices repeat but they repeat vertices in question and still correct.........
1 question here . 2nd one not able to find.
mine answer is incorrect here because i didnt read question carefully i write correct instead of incorrect but 2 nd and 4th option vertices repeats and simple path just take one time vertices