Definitions for "Page fault"
Keywords:  interrupt, fault, virtual, memory, swap
(n.) An interrupt caused by the failure to find a needed page in virtual memory.
The interrupt that occurs when software attempts to read from or write to a virtual memory location that is marked “not present.” The mapping hardware of a virtual memory system maintains status information about every page in the virtual address space. A page either is mapped onto a physical address or is not present in physical memory. When a read or write to an unmapped virtual address is detected, the memory management hardware generates the page fault interrupt. The operating system must respond to the page fault by swapping in the data for the page and updating the status information in the memory management unit.
An interrupt that occurs when a program requests data that is not currently in virtual memory.
Keywords:  perfectly, ram, error, disk, held
A call for a data page that is not held in RAM and pages out to disk for it. Sounds like an error but it is perfectly normal.
a program notification that occurs when a page that is marked as not in main storage is referred to be an active program
Keywords:  triggered, event, moved
an event that is triggered when a page is to be moved
an exception generated by a reference to a page that is not mapped into a working set.