yuktiiii

What is the meaning of last sentence in this question?
It means that rotating the same arrangement around the table doesn’t count as a new one. Only when the knights’ positions change relative to one another is it considered a different arrangement.
For example, if A, B, C, D, and E are seated in that order around the table, rotating them to B, C, D, E, A is the same arrangement because everyone has the same neighbors. But if their relative order changes, like A, C, B, D, E, that’s a different arrangement.
P.S. And it’s always better to post your doubts directly in the
question’s topic, not in this thread.