Working of ready boost feature in Windows 7-10

Connect a USB stick to a Windows computer – even on Windows 8 – and Windows will ask if you want to speed up your system using
ReadyBoost. But what exactly is ReadyBoost, and will it actually speed up your computer?
ReadyBoost was introduced in Windows Vista, where it was a heavily promoted feature. Unfortunately, ReadyBoost isn’t a silver bullet that will make your computer faster, although it may be useful in some limited circumstances.

How ReadyBoost Works
ReadyBoost works in conjunction with SuperFetch. SuperFetch, also introduced in Windows Vista, monitors the programs you use on your computer and automatically loads their application files and libraries into your computer’s memory (RAM) ahead of time. When you launch the application, it will start faster — your computer reads its files from memory, which is faster, instead of from disk, which is slower. Empty RAM doesn’t do any good, so using it as a cache for frequently accessed applications can increase your computer’s responsiveness.
SuperFetch normally uses your computer’s memory – it caches these files in your RAM. However, SuperFetch can also work with a USB stick – that’s ReadyBoost in action. When you connect a USB drive to your computer and enable ReadyBoost, Windows will store SuperFetch data on your USB drive, freeing up system memory. It’s faster to read various small files from your USB stick than it is to read them from your hard drive, so this can theoretically improve your system’s performance.