Windows 7: How does ReadyBoost work?

In a layman language we can say that flash drive can be used as RAM with the help of 'ReadyBoost'. But the fact is that a flash drive cannot replace or work like a RAM.

Flash drive is too much slower than a RAM. I explored some articles about physical memory, virtual memory and readyboost. So there are a few questions wandering in my mind.

Hard drives get slow because of their seek time. Does readyboost cache data into flash memory so that latency caused by seek time, in HDD, can be eliminated?

Is ReadyBoost only caching service?

Readyboost is a cache for Superfetch. That is pretty much it.

You are correct, flash memory is indeed (a lot) slower than RAM - however, it's still orders of magnitude faster (especially in seek time) than a mechanical disk, thus using a USB key or a CF flash device to extend the SuperFetch cache is still a very good idea and does provide performance benefits on machines with very small amounts of RAM, or that do very large amounts of random disk I/O.

It isn't going to totally reduce seek time for everything, but for things that are in the cache, yes - the I/O request is satisfied by the SuperFetch cache in RAM or on a memory device as long as the data is there in the cache.

Yes, it provides an extension of the SuperFetch cache in system RAM onto removable memory devices, increasing the size / capacity that SuperFetch can use.