To move one article, keep the mouse button down on its name and drag it to its new page.
To copy one article, hold down the mouse on its name and keep the ""Shift"" keybord key pressed until you drop the article in its new page.
To copy one article creates a link with the destination page. The article will then be displayed in the 2 pages.
Each content update made on one article in one page will be displayed in the other context page, because it is the same article.
But, one "copied", the article will have 2 separated context, one for each page.