Paging is actually a minimum memory, which can be swap in and swap out from Memory. In modern Server operating systems, we can use Multiple Page Size Support. That actually helps to tune OS performance, depending on type of applications.
Segmentation is actually a way to keep similar objects in one place. For example: you can have your stack stuffs in one place (Stack Segment), Binary code in another place (text segment), and data in another place (Data and BSS segment). Linux doesn’t have segment architecture. AIX has Segment architecture.