system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:How do computers organize their memory?

Is the memory on a computer like a bucket of water? when you delete something a little water is poured out making room for more water/memory.Or is it like a bookshelf were books are taken from certain spots leaving patches for new books/memory.
gpt
It starts like the bookshelf. However, from time to time the computer will momentarily pause other operations in order to push things together, in order to combine lots of little spaces into bigger, easier-to-use spaces.