what is the actual cache memory & what's does?

what is the actual cache memory & what's does?

Simple vocabulary. cache is a "go between" memory, cpu, and/or harddrive. The larger it is, the more data it can give support to move around.

Best way to picture this is to say-so a bathtub is your bump memory (where programs run at, a lake is the harddrive (where data/programs are stored). The cache would be the bucket that moves the marine (programs/data) from the hardrive to the memory in lay down to run.

It is also able to hold that information to wait until it's needed. Like when the cpu is trying to run calculation, the cache helps keep hold of the data moving so the cpu doesn't enjoy to wait for more information to be sent to it.
Cache memory is high speed memory that sits close to the processor. Basically, when the processor have to do work it must do it from within its registers (registers are also memory cells). In instruct to do this, it might have to nouns the values from memory into its registers. The first place it looks is cache memory, and if it finds it it copies it to registers to perform its operation. If it doesn't find it in L1 cache, it checks L2 cache, next it checks system memory, and the OS might have to page the memory from a page database. Note that each of these operation takes longer so its more preferable to own your data surrounded by L1 or L2 cache (and therefore better to own a larger cache).
In computer science, a cache is a collection of data duplicating resourceful values stored elsewhere or computed earlier, where on earth the original notes is expensive (usually in jargon of access time) to fetch or compute relative to reading the cache. Once the data is stored surrounded by the cache, future use can be made by access the cached copy rather than re-fetching or recomputing the inspired data, so that the average access time is lower.