To split a document up into multiple files. But the disadvantage is that Latex only has single includes - so you can not split a document up that much. (This i

To split a document up into multiple files. But the disadvantage is that Latex only has single includes - so you can not split a document up that much. (This is also a problem if you use images with equations such as those created by xfig (i.e. pure latex or PSTex PicTex). Usually most people would like to include an image as a separate file.