What is different between "pager" and "Lazy swapper"?

Question

I'm reading a book, operating system concepts (written by abraham silberschatz), in chapter 9 virtual memory, there are terms Lazy swapper and pager.

I can't figure out what is different between Lazy swapper and pager.

Swapper is just doing the entire process into memory, whereas lazy swapper is doing swapping a page rather than entire process.

Is it pager?

Answer 1

A demand paging system is quite similar to a paging system with swapping. When we want to execute a process, we swap it into memory. Rather than swapping the entire process into memory, however, we use a lazy swapper called pager. But both do it in a different way. Swapper Copies all pages related to a whole process(used in earlier days). But Lazy swapper do it Page-by-Page, That's why it is lazy... jokes apart