The archive store is where deleted nodes go. Similar to the "recycle bin" of windows.
In some situations the administrator can "un-delete" nodes from the archive store.
You can configure what should happen when nodes are deleted. The choices out of the box are oblivion or the archive store. You can also configure multiple archive stores, one for each non archive store.
Your posting became garbaled in the middle so could you try again to say what you mean by "archive".