A hard drive is static or nonvolatile memory.
matters your hard drive can hold 5gb or 500gb in lmost all cases yes hard drive has most memory.
its memory
no
virtual memory
Decide what type of hard drive or memory to add.
A 1TB drive has aprox. 1000GB of memory. So 1TB has 250GB more memory than any 750GB drive.
yes you can all you need to do is have the memory unit and the hard drive in the 360. Then go to system setting and go to memory the go to the memory unit and go to the profile the do copy to hard drive.
There are special procedures to follow when changing the hard drive which contains the memory for the PS3. If you are upgrading or otherwise replacing a hard drive you must follow the procedures to reduce any memory loss. See related link
RAM Drive
RAM
you can have as much as you like. you would just have to get a bigger hard drive, memory stick, external hard drive or server etc.
It is what goes in a phone that holds all of your memory