A cache transparently stores data so that future requests for that data can be served faster. A buffer, on the other hand, temporarily stores data while the data is the process of moving from one place to...

RAM is volatile and used for both read and write. ROM is non-volatile and only used for reading. Memory on the RAM is erased when the computer is switched off.

Hardware is the physical aspect of the computer, the thing we can touch, such as monitor, hard drive, etc. Software is the non-physical aspect which includes the operating system, applications, programs, etc.