I think it is a good reference
https://gateoverflow.in/9566/segmentation
if segmentation is variable partitioning then it is free from internal fragmentation , but not from external fragmentation
segmentation is better than static partitioning. I think it is not best, as it causes external fragmentation. Some times paging gives better memory utilization than segmentation
For ur 2nd question ans is https://gateoverflow.in/33954/segmented-paging-and-paged-segmentation
64.3k questions
77.9k answers
244k comments
80.0k users