In Confluence, you have the option to Archive an Space which will make it to not be searchable and also another modifications.

However, you cannot move any page to this space. This will be a feature request to allow the archived space to be displayed as one of the options to move the page.

Why? For example, the user would like to use the space as a general archive for the whole instance. If a page is outdated or some other content will not be important, the page could be moved to there.