When the computer is turned off, the
ROM keeps all its data and memory.
For example, date and clock.
RAM
The letters stand for
'random access memory
The RAM clears itself every
time the computer is turned off
Dynamic RAM
Dynamic RAM is the
most common
memory in use today
It takes up more room on a chip
Each memory cell holds one bit of
information and is made up of two parts: a
transistor and a capacitor. These are, of
course, extremely small transistors and
capacitors so that millions of them can fit
on a single memory chip.
Static RAM
Static RAM uses a completely different
technology. In static RAM, a form of flip-flop
holds each bit of memory. A flip-flop for a
memory cell takes 4 or 6 transistors along with
some wiring, but never has to be refreshed.
This makes static RAM significantly faster than
dynamic RAM. However, because it has more
parts, a static memory cell takes a lot more
space on a chip than a dynamic memory cell.
Therefore you get less memory
per chip, and that makes static
RAM a lot more expensive.