system
8
What are you trying to ask? Windows uses a memory manager to assign memory to programs as they need it for efficient operation, and they return it when they no longer need it. The programs themselves use memory to avoid paging/shuttling in and out and this makes them run more quickly and efficiently. Time and space is still a tradeoff. So depending on what activity is occurring or being anticipated, Avast! memory will move up and down fairly quickly. My current is attached, but a minute ago usage was below 5000K.