DNS cache snooping is not a term the author just made up, it is known and discussed by some notable
DNS implementation developers, and a few interested DNS administrators have probably at least heard of it.
Cache coherence refers to the integrity of data stored in local caches of a shared resource. Cache coherence is a special case of memory coherence. When clients in a system, particularly CPUs in a multiprocessing system cache occurs.
Virtual Memory is a way of extending a computers memory by using a disk file to simulate add'l memory space. The OS keeps track of these add'l memory addresses on the hard disk called pages, and the operation in bringing in pages is called page fault.
The instruction sets can be differentiated by
It turns out that caching is an important computer-science process that appears on every computer in a variety of forms. There are memory caches, hardware and software disk caches, page caches and more. Virtual memory is even a form of caching.
Caching is a technology based on the memory subsystem of your computer. The main purpose of a cache is to accelerate your computer while keeping the price of the computer low. Caching allows you to do your computer tasks more rapidly. Cache technology is the use of a faster but smaller memory type to accelerate a slower but larger memory type. A cache has some maximum size that is much smaller than the larger storage area. It is possible to have multiple layers of cache.
A computer is a machine in which we measure time in very small increments. When the microprocessor accesses the main memory (RAM), it does it in about 60 nanoseconds (60 billionths of a second). That's pretty fast, but it is much slower than the typical microprocessor. Microprocessors can have cycle times as short as 2 nanoseconds, so to a microprocessor 60 nanoseconds seems like an eternity.