When you view messages in a Search Folder, you can perform some actions on them right there. For instance, you can copy, delete, or move them between your conventional folders. And, of course, you can read them (or simply mark them as read). You can do all of these things from a Search Folder just as you would from a conventional folder (by dragging or right-clicking the message). However, you can't drag a message into or out of a Search Folder; the only way a message can appear in a Search Folder is if it meets the criteria that you set up for the folder.
Need an easier way to think about it? Take a look at the picture above, in which we use the action of deleting as an example:
When you delete a message that appears in a Search Folder, the message is also deleted from your mailbox.
When you delete the Search Folder itself, the messages that appeared inside it are unaffected by the deletion. This is because the Search Folder is merely a container in which Outlook displays messages; deleting the container has no effect on the messages.