By giving Minecraft more memory or allocate memory, you give it more resources to work with. This can help the game run more smoothly and make it less likely that you’ll get the “Out of Memory ...

Memory garbage collection is only one of the applications of reference counting; it is also used for deallocation control of system objects, Windows COM objects, and file system blocks or files.

If you see Minecraft has run out of memory error, your might have to allocate more memory to Minecraft, Reduce video settings, etc.