> means that whatever number or value on the left is larger than the one on the right for example:
4 > 3
< means the opposite whatever number or value on the right is larger than the one on the left for example:
5 < 6
So with 1/6 and -3/4 to first understand it we must make the denominator the same so we times 1/6 by 4 to get 4/24 and we times -3/4 by 6 to get - 18/24 now if we ignore the - then we know that -18/24 is larger but since there is a - it means that 18/24 is negative and therefore below 0 so is below 4/24