交换技术、覆盖技术、分页技术

交换技术：当需要执行某个进程时，整个进程从交换分区中移动到主存中。进程的大小不能超过内存可用空间的大小。

覆盖技术：与交换技术一样，其区别是需要程序员自己实现其数据的移动。

分页技术：仅将需要的页面从交换分区中移动到主存中。进程大小可以超过可用内存的大小，只要足够容纳所需的分页即可。

 

What is the difference between Swapping and Paging?

Swapping: Whole process is moved from the swap device to the main memory for execution. Process size must be less than or equal to the available main memory. It is easier to implementation and overhead to the system. Swapping systems does not handle the memory more flexibly as compared to the paging systems. Overlay is implemented by the programmer.

Paging: Only the required memory pages are moved to main memory from the swap device for execution. Process size does not matter.